demonstrate basic http authentication (#605)

src/SUMMARY.md

@@ -65,3 +65,4 @@
     - [Making Requests](web/clients/requests.md)
     - [Calling a Web API](web/clients/apis.md)
     - [Downloads](web/clients/download.md)
+    - [Web Authentication](web/clients/authentication.md)

src/web.md

@@ -39,6 +39,12 @@
 | [Make a partial download with HTTP range headers][ex-progress-with-range] | [![reqwest-badge]][reqwest] | [![cat-net-badge]][cat-net] |
 | [POST a file to paste-rs][ex-file-post] | [![reqwest-badge]][reqwest] | [![cat-net-badge]][cat-net] |
 
+## Web Authentication
+
+| Recipe | Crates | Categories |
+|--------|--------|------------|
+| [Basic Authentication][ex-basic-authentication] | [![reqwest-badge]][reqwest] | [![cat-net-badge]][cat-net] |
+
 [ex-extract-links-webpage]: web/scraping.html#extract-all-links-from-a-webpage-html
 [ex-check-broken-links]: web/scraping.html#check-a-webpage-for-broken-links
 [ex-extract-mediawiki-links]: web/scraping.html#extract-all-unique-links-from-a-mediawiki-markup
@@ -64,4 +70,6 @@
 [ex-progress-with-range]: web/clients/download.html#make-a-partial-download-with-http-range-headers
 [ex-file-post]: web/clients/download.html#post-a-file-to-paste-rs
 
+[ex-basic-authentication]: web/clients/authentication.html#basic-authentication
+
 {{#include links.md}}

src/web/clients/authentication.md

@@ -0,0 +1,5 @@
+# Authentication
+
+{{#include authentication/basic.md}}
+
+{{#include ../../links.md}}

src/web/clients/authentication/basic.md

@@ -0,0 +1,28 @@
+## Basic Authentication
+
+[![reqwest-badge]][reqwest] [![cat-net-badge]][cat-net]
+
+Uses [`reqwest::RequestBuilder::basic_auth`] to perform a basic HTTP authentication.
+
+```rust,edition2018,no_run
+use reqwest::blocking::Client;
+use reqwest::Error;
+
+fn main() -> Result<(), Error> {
+    let client = Client::new();
+
+    let user_name = "testuser".to_string();
+    let password: Option<String> = None;
+
+    let response = client
+        .get("https://httpbin.org/")
+        .basic_auth(user_name, password)
+        .send();
+
+    println!("{:?}", response);
+
+    Ok(())
+}
+```
+
+[`reqwest::RequestBuilder::basic_auth`]: https://docs.rs/reqwest/*/reqwest/struct.RequestBuilder.html#method.basic_auth