README for nu-json. Related to nushell/nushell#8253 (#8289)

I propose to add such a README file for the nu-json crate.
The crate is good, it is used also by others. However, on crates.io [its
page](https://crates.io/crates/nu-json) looks uninformative.

Related to https://github.com/nushell/nushell/issues/8253

---------

Co-authored-by: ygguser <there_is@no.email>

crates/nu-json/CHANGELOG.md

@@ -0,0 +1,187 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+<!-- Use this as a template
+## [X.Y.Z] - YYYY-MM-DD
+### Added
+- for new features.
+
+### Changed
+- for changes in existing functionality.
+
+### Deprecated
+- for soon-to-be removed features.
+
+### Removed
+- for now removed features.
+
+### Fixed
+- for any bug fixes.
+
+### Security
+- in case of vulnerabilities.
+-->
+ 
+# [0.76.0] - 2023-02-21
+
+### Changed
+
+- Disable auto-benchmark harness for this crate
+ 
+# [0.75.0] - 2023-01-31
+
+### Changed
+
+- Removing unnecessary comments from the code
+- Use variable names directly in the format strings 
+- Apply more recent/nightly clippy lints
+ 
+# [0.73.0] - 2022-12-20
+
+### Changed
+
+- Remove unused dev-dependencies
+- The lazy_static crate has been replaced by once_cell
+ 
+# [0.71.0] - 2022-11-29
+
+### Fixed
+
+- Fixed json parsing
+ 
+# [0.71.0] - 2022-11-08
+
+### Changed
+
+- Run a round of clippy --fix to fix a ton of lints
+
+# [0.67.0] - 2022-08-16
+
+### Added
+
+- Add repository info to all workspace crates
+
+### Changed
+
+- Replace the regex crate with the fancy-regex crate
+ 
+# [0.66.0] - 2022-07-26
+
+### Fixed
+
+- Prevents panic when parsing JSON containing large number
+ 
+# [0.64.0] - 2022-06-15
+
+### Changed
+
+- Address lints from clippy for beta/nightly
+
+# [0.60.1] - 2022-03-27
+
+### Changed
+
+- Align all of the serde_json crates to the same version (`serde_json = "0.1.39"` --> `serde_json = "0.1"`)
+
+# [0.60.0] - 2022-03-22
+
+### Added
+
+- Adds tab indentation option for JSON files. 
+
+### Changed
+
+- Changing the name of the parent project: 'The Nu Project' --> 'The Nushell Project'
+
+# [0.59.1] - 2022-03-02
+
+### Added
+
+- Add indent flag to to json (first draft) 
+
+### Fixed
+
+- Fix to json escape logic
+- Clippy fixes 
+
+### Changed
+
+- Update this cargo crate to edition 2021
+- Strip trailing whitespace in files
+
+# [0.42.0] - 2021-12-28
+
+### Fixed
+
+- fix issue #559: to json -r serializes datetime without spaces
+
+### Changed
+
+- add in a raw flag in the command to json
+
+# [0.41.0] - 2021-12-07
+
+### Changed
+
+- avoid unnecessary allocation (serialization)
+
+# [0.37.0] - 2021-09-14
+
+### Changed
+
+- Add general refactorings
+
+# [0.31.0] - 2021-05-11
+
+### Fixed
+
+- Clippy fixes for new Rust version
+
+# [0.29.2] - 2021-04-06
+
+### Fixed
+
+- Fix typos and capitalization of "Unicode"
+
+# [0.29.0] - 2021-03-30
+
+### Fixed
+
+- Fix warnings for Rust 1.51
+
+# [0.28.0] - 2021-03-09
+
+### Changed
+
+- Preserve order when serializing/deserialize json by default.
+
+# [0.27.0] - 2021-02-16
+
+### Fixed
+
+- Fix latest clippy warnings
+
+# [0.25.2] - 2021-01-11
+
+### Changed
+
+- Update num-traits requirement from 0.1.32 to 0.2.14
+
+# [0.25.0] - 2021-01-05
+
+### Fixed
+
+- Rust 1.49 Clippy Fixes
+
+# [0.22.0] - 2020-11-22
+
+### Changed
+
+- Fork of serde-hjson
+- The crate added to the 'Nu Project'
+- Added Cargo.toml
+- LICENSE file added
+- Bump version to 0.22 according to the parent project

crates/nu-json/README.md

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+# nu-json
+
+[![crate](https://img.shields.io/crates/v/nu-json.svg?style=flat-square)](https://crates.io/crates/nu-json)
+
+> a fork of [serde_hjson](https://crates.io/crates/serde-hjson). 
+
+> The changes made to this crate are kept in [CHANGELOG](/crates/nu-json/CHANGELOG.md).
+
+
+The Rust implementation of Hjson is based on the [Serde JSON Serialization Library](https://github.com/serde-rs/json). 
+
+This crate is a Rust library for parsing and generating Human JSON [Hjson](https://hjson.github.io). It is built upon [Serde](https://github.com/serde-rs/serde), a high performance generic serialization framework.
+
+# Install
+
+This crate works with Cargo and can be found on [crates.io](https://crates.io/crates/nu-json) with a `Cargo.toml` like:
+
+```toml
+[dependencies]
+serde = "1"
+nu-json = "0.76"
+```
+
+## From the Commandline
+
+Add with:
+```
+ cargo add serde
+ cargo add nu-json
+```
+
+# Usage
+
+```rust
+extern crate serde;
+extern crate nu_json;
+
+use nu_json::{Map,Value};
+
+fn main() {
+
+    // Now let's look at decoding Hjson data
+
+    let sample_text=r#"
+    {
+        # specify rate in requests/second
+        rate: 1000
+        array:
+        [
+            foo
+            bar
+        ]
+    }"#;
+
+    // Decode and unwrap.
+    let mut sample: Map<String, Value> = nu_json::from_str(&sample_text).unwrap();
+
+    // scope to control lifetime of borrow
+    {
+        // Extract the rate
+        let rate = sample.get("rate").unwrap().as_f64().unwrap();
+        println!("rate: {}", rate);
+
+        // Extract the array
+        let array : &mut Vec<Value> = sample.get_mut("array").unwrap().as_array_mut().unwrap();
+        println!("first: {}", array.get(0).unwrap());
+
+        // Add a value
+        array.push(Value::String("tak".to_string()));
+    }
+
+    // Encode to Hjson
+    let sample2 = nu_json::to_string(&sample).unwrap();
+    println!("Hjson:\n{}", sample2);
+}
+```
+# DOCS
+
+At the moment, the documentation on [serde_hjson](https://docs.rs/serde-hjson/0.9.1/serde_hjson/) / [serde_json](https://docs.rs/serde_json/1.0.93/serde_json/) is also relevant for nu-json.