diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index 777686a..2cafffd 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -19,15 +19,13 @@ assignees: ''
 - [] [mas-cli/tap](https://github.com/mas-cli/homebrew-tap)
 - [] `.pkg` installer from [releases](https://github.com/mas-cli/mas/releases)
 - [] Built from source
-   - Fork/branch: ? (e.g. mas-cli/master)
-   - Xcode version: 10.?
+  - Fork/branch: ? (e.g. mas-cli/master)
+  - Xcode version: 10.?
 
 ## Describe the Bug
 
 > A clear and concise description of what the bug is.
 
-
-
 ## To Reproduce
 
 Steps to reproduce the behavior:
@@ -41,29 +39,20 @@ Steps to reproduce the behavior:
 
 > A clear and concise description of what you expected to happen.
 
-
-
 ## Actual Behavior
 
 > A clear and concise description of what actually happened.
 
-
-
 ## Screenshots, Terminal Output
 
 > If applicable, add screenshots to help explain your problem.
 
-
-
-```
+```bash
 $ mas command
 ...
 ```
 
-
 ## Additional Context
 
 > Add any other context about the problem here.
 > Did it work in a previous version?
-
-
diff --git a/.markdownlint.json b/.markdownlint.json
new file mode 100644
index 0000000..f2d608c
--- /dev/null
+++ b/.markdownlint.json
@@ -0,0 +1,4 @@
+{
+  "MD013": { "line_length": 120 },
+  "MD033": { "allowed_elements": ["h1", "img"] }
+}
diff --git a/Brewfile b/Brewfile
index 0afd05f..4bea1f5 100644
--- a/Brewfile
+++ b/Brewfile
@@ -1,3 +1,4 @@
+brew "markdownlint-cli"
 brew "shfmt"
 brew "swift-format"
 brew "swiftformat"
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
index 6f43dcb..e443d1d 100644
--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -68,9 +68,9 @@ members of the project's leadership.
 ## Attribution
 
 This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
-available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+available at <https://www.contributor-covenant.org/version/1/4/code-of-conduct.html>
 
 [homepage]: https://www.contributor-covenant.org
 
 For answers to common questions about this code of conduct, see
-https://www.contributor-covenant.org/faq
+<https://www.contributor-covenant.org/faq>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 367d941..01ba479 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -6,34 +6,36 @@ We love pull requests from everyone. By participating in this project, you agree
 
 - Make sure you have a [GitHub account](https://github.com/join).
 - [Open an issue](https://github.com/mas-cli/mas/issues/new) to simply ask a question or request a new feature.
-- Search for similar issues with the [ERROR MESSAGE](https://github.com/mas-cli/mas/issues?utf8=%E2%9C%93&q=is%3Aopen+ERROR+MESSAGE) you are exeriencing.
+- Search for similar issues with the
+[ERROR MESSAGE](https://github.com/mas-cli/mas/issues?utf8=%E2%9C%93&q=is%3Aopen+ERROR+MESSAGE)
+you are exeriencing.
 - If one doesn't exist, [open a new issue](https://github.com/mas-cli/mas/issues/new)
-   - Clearly describe the issue including steps to reproduce when it is a bug.
-   - Include the earliest version of `mas` that you know has the issue.
-   - Include your macOS version.
+  - Clearly describe the issue including steps to reproduce when it is a bug.
+  - Include the earliest version of `mas` that you know has the issue.
+  - Include your macOS version.
 
 ## Making Changes
 
 - [Fork the repository](https://github.com/mas-cli/mas#fork-destination-box) on GitHub.
-- Cone your fork  
+- Cone your fork
   `git clone git@github.com:your-username/mas.git`
 - Create a topic branch from where you want to base your work.
-   - This is usually the `master` branch.
-   - To quickly create a topic branch based on `master`, run  
+  - This is usually the `master` branch.
+  - To quickly create a topic branch based on `master`, run
      `git checkout -b awesome-feature master`
-   - Please avoid working [directly on the master branch](https://softwareengineering.stackexchange.com/questions/223400/when-should-i-stop-committing-to-master-on-new-projects).
-   - Make commits of logical units.
+  - Please avoid working [directly on the master branch](https://softwareengineering.stackexchange.com/questions/223400/when-should-i-stop-committing-to-master-on-new-projects).
+  - Make commits of logical units.
 - Run script/format before committing your changes. Fix anything that isn't automatically fixed by the linters.
 - Push your topic branch to your fork and [submit a pull request](https://github.com/mas-cli/mas/compare/master...your-username:topic-branch).
 
 Some things that will increase the chance that your pull request is accepted:
 
 - Write tests. (Tests target is still [in progress](https://github.com/mas-cli/mas/issues/123))
-   - If you need help with tests, feel free to open a PR in the meantime and just ask for some help.
-   - Add "[WIP]" to the title of your PR to indicate that it's not ready to be merged.
+  - If you need help with tests, feel free to open a PR in the meantime and just ask for some help.
+  - Add "[WIP]" to the title of your PR to indicate that it's not ready to be merged.
 - Follow our [style guide](docs/style.md).
 - Write a [good commit message](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html).
-   - Including [appropriate emoji](https://gitmoji.carloscuesta.me/) in the first line of commit messages is fun :wink:.
+  - Including [appropriate emoji](https://gitmoji.carloscuesta.me/) in the first line of commit messages is fun :wink:.
 
 ## Becoming a Contributor
 
@@ -50,7 +52,8 @@ to this project, but must remain an owner. By becoming a contributor, you agree
 
 - This project follows [trunk-based development](https://trunkbaseddevelopment.com/), where `master` is our trunk.
 - Release commits will be tagged in the format: `v1.2.3`.
-- Once releases are tagged, high-level release notes are published on the [releases](https://github.com/mas-cli/mas/releases) page.
+- Once releases are tagged, high-level release notes are published on the
+[releases](https://github.com/mas-cli/mas/releases) page.
 
 See GitHub's post on creating [Contributing Guidelines](https://github.com/blog/1184-contributing-guidelines)
 if you would like to set up something like this for your projects.
diff --git a/README.md b/README.md
index 85eedb3..9ed4f82 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[<p align="center"><img src="mas-cli.png" alt="mas-cli" width="450" height="auto"></p>][mas-cli]
+<h1 align="center"><img src="mas-cli.png" alt="mas-cli" width="450" height="auto"></h1>
 
 # mas-cli
 
@@ -109,7 +109,8 @@ $ mas purchase 768053424
 ```
 
 > Please note that you may have to re-authenticate yourself in the App Store to complete the purchase.
-This is the case if the application is not free or if you configured your account not to remember the credentials for free purchases.
+This is the case if the application is not free or if you configured your account not to remember the
+credentials for free purchases.
 
 Use `mas outdated` to list all applications with pending updates.
 
@@ -183,9 +184,14 @@ docs for more details.
 
 ## 💥 When something doesn't work
 
-If you see the error "This redownload is not available for this Apple ID either because it was bought by a different user of the item was refunded or cancelled.", it's probably because you haven't installed the app through the App Store yet. See [#46](https://github.com/mas-cli/mas/issues/46#issuecomment-248581233).
+If you see this error, it's probably because you haven't installed the app through the App Store yet.
+See [#46](https://github.com/mas-cli/mas/issues/46#issuecomment-248581233).
+> This redownload is not available for this Apple ID either because it was bought by a different user of the
+> item was refunded or cancelled.
 
-If `mas` doesn't work for you as expected (e.g. you can't update/download apps), run `mas reset` and try again. If the issue persists, please [file a bug](https://github.com/mas-cli/mas/issues/new)! All your feedback is much appreciated ✨
+If `mas` doesn't work for you as expected (e.g. you can't update/download apps), run `mas reset` and try again.
+If the issue persists, please [file a bug](https://github.com/mas-cli/mas/issues/new).
+All your feedback is much appreciated! ✨
 
 ## 📺 Using `tmux`
 
diff --git a/docs/style.md b/docs/style.md
index 6de3332..3e24c3d 100644
--- a/docs/style.md
+++ b/docs/style.md
@@ -2,18 +2,21 @@
 
 - Use `script/format` to automatically fix a number of style violations.
 - Remove unnecessary whitespace from the end of lines.
-   - Use `script/lint` to look for these before committing.
-   - Note that [two trailing spaces](https://gist.github.com/shaunlebron/746476e6e7a4d698b373)
+  - Use `script/lint` to look for these before committing.
+  - Note that [two trailing spaces](https://gist.github.com/shaunlebron/746476e6e7a4d698b373)
      is intentional in markdown documents to create a line break like `<br>`, so these should _not_ be removed.
 - End each file with a [newline character](https://unix.stackexchange.com/questions/18743/whats-the-point-in-adding-a-new-line-to-the-end-of-a-file#18789).
 
-# Swift
+## Swift
 
 [Sample](sample.swift)
 
-- Avoid [force unwrapping optionals](https://blog.timac.org/2017/0628-swift-banning-force-unwrapping-optionals/) with `!` in production code
-   - Production code is what gets shipped with the app. Basically, everything under the [`mas-cli/`](https://github.com/mas-cli/mas/tree/master/mas-cli) folder.
-   - However, force unwrapping is **encouraged** in tests for less code and tests _should_ break when any expected conditions aren't met.
+- Avoid [force unwrapping optionals](https://blog.timac.org/2017/0628-swift-banning-force-unwrapping-optionals/)
+with `!` in production code
+  - Production code is what gets shipped with the app. Basically, everything under the
+  [`mas-cli/`](https://github.com/mas-cli/mas/tree/master/mas-cli) folder.
+  - However, force unwrapping is **encouraged** in tests for less code and tests
+  _should_ break when any expected conditions aren't met.
 - Prefer `struct`s over `class`es wherever possible
 - Default to marking classes as `final`
 - Prefer protocol conformance to class inheritance
diff --git a/script/format b/script/format
index a14c364..b888429 100755
--- a/script/format
+++ b/script/format
@@ -13,13 +13,17 @@
 
 echo "==> 🚨 Formatting mas"
 
-for LINTER in shfmt swift-format swiftformat swiftlint; do
+for LINTER in markdownlint shfmt swift-format swiftformat swiftlint; do
   if [[ ! -x "$(command -v ${LINTER})" ]]; then
     echo "error: ${LINTER} is not installed. Run 'script/bootstrap' or 'brew install ${LINTER}'."
     exit 1
   fi
 done
 
+echo
+echo "--> 🖊 Markdown"
+markdownlint --config .markdownlint.json --fix .github .
+
 echo
 echo "--> 🕊️ Swift"
 for SOURCE in Package.swift Sources Tests; do
diff --git a/script/lint b/script/lint
index 93503ab..d4e5b0b 100755
--- a/script/lint
+++ b/script/lint
@@ -12,7 +12,7 @@
 
 echo "==> 🚨 Linting mas"
 
-for LINTER in git swift-format swiftformat swiftlint; do
+for LINTER in git markdownlint shfmt swift-format swiftformat swiftlint; do
   if [[ ! -x "$(command -v ${LINTER})" ]]; then
     echo "error: ${LINTER} is not installed. Run 'script/bootstrap' or 'brew install ${LINTER}'."
     exit 1
@@ -22,6 +22,10 @@ done
 echo "--> 🌳 Git"
 git diff --check
 
+echo
+echo "--> 🖊 Markdown"
+markdownlint --config .markdownlint.json .github .
+
 echo
 echo "--> 🕊️ Swift"
 for SOURCE in Package.swift Sources Tests; do