Add CONTRIBUTING guide

.githooks/commit-msg

@@ -0,0 +1,10 @@
+#!/bin/sh
+changelog="CHANGELOG.md"
+msgfile="$1"
+msg=$(head -n1 "$msgfile")
+
+# Ensure changelog contains bullet for the commit message
+if ! grep -Fq "- $msg" "$changelog"; then
+  sed -i "/^## \[Unreleased\]/a - $msg" "$changelog"
+  git add "$changelog"
+fi

CHANGELOG.md

@@ -0,0 +1,12 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+- upcoming changes
+
+## [0.1.22] - 2025-06-04
+- Added `CONTRIBUTING.md` with setup and test instructions.

CONTRIBUTING.md

@@ -0,0 +1,21 @@
+# Contributing to TSDataStructure
+
+Thank you for considering contributing! Follow these steps to get started.
+
+## Setup
+
+1. Install dependencies:
+   ```bash
+   npm install
+   ```
+2. Run the linter and build the project:
+   ```bash
+   npm run lint
+   npm run build
+   ```
+3. Execute the test suite:
+   ```bash
+   npm test
+   ```
+
+Please ensure all tests pass before submitting a pull request. Commit messages should be clear and descriptive.

DEVELOPMENT_PLAN.md

@@ -23,8 +23,8 @@ This document outlines possible improvements and future developments for the `TS
 ## Documentation
 
 - **API Examples**: Expand the README with practical examples demonstrating each data structure in real-world scenarios.
-- **Contribution Guide**: Provide a `CONTRIBUTING.md` describing how to set up the project, run tests, and submit pull requests.
-- **Changelog**: Maintain a `CHANGELOG.md` to track notable changes between releases.
+- **Contribution Guide**: Provide a `CONTRIBUTING.md` describing how to set up the project, run tests, and submit pull requests. *(Implemented)*
+- **Changelog**: Maintain a `CHANGELOG.md` to track notable changes between releases. *(Implemented)*
 
 ## Packaging and Distribution
 

README.md

@@ -500,9 +500,11 @@ If you have an advice, please feel free to contact with me
 
 ## Git Hooks
 
-This project uses a pre-commit hook stored in `.githooks/pre-commit` to
-automatically bump the package patch version each time you commit. Enable the
-hooks with the following command:
+This project uses git hooks stored in the `.githooks` directory. The
+`pre-commit` hook automatically bumps the package patch version each time you
+commit, while the `commit-msg` hook appends the commit message to the
+`CHANGELOG.md` under the *Unreleased* section. Enable the hooks with the
+following command:
 
 ```bash
 git config core.hooksPath .githooks