From ff040e0cd86ec43f0d17f0a08546ed17b150d312 Mon Sep 17 00:00:00 2001
From: Bakhtier Gaibulloev <slashmsu@gmail.com>
Date: Wed, 4 Jun 2025 10:24:31 +0200
Subject: [PATCH 1/3] Add contribution guide

---
 CONTRIBUTING.md     | 21 +++++++++++++++++++++
 DEVELOPMENT_PLAN.md |  2 +-
 2 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..fce9315
--- /dev/null
+++ b/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.
diff --git a/DEVELOPMENT_PLAN.md b/DEVELOPMENT_PLAN.md
index 64556e9..7342ee7 100644
--- a/DEVELOPMENT_PLAN.md
+++ b/DEVELOPMENT_PLAN.md
@@ -23,7 +23,7 @@ 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.
+- **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.
 
 ## Packaging and Distribution

From 2bf78cab5982877706fe211dd113cbb28e1e6eda Mon Sep 17 00:00:00 2001
From: Bakhtier Gaibulloev <slashmsu@gmail.com>
Date: Wed, 4 Jun 2025 10:43:03 +0200
Subject: [PATCH 2/3] Add changelog and mark task complete

---
 CHANGELOG.md        | 12 ++++++++++++
 DEVELOPMENT_PLAN.md |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..04320a8
--- /dev/null
+++ b/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.
diff --git a/DEVELOPMENT_PLAN.md b/DEVELOPMENT_PLAN.md
index 7342ee7..c366785 100644
--- a/DEVELOPMENT_PLAN.md
+++ b/DEVELOPMENT_PLAN.md
@@ -24,7 +24,7 @@ This document outlines possible improvements and future developments for the `TS
 
 - **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. *(Implemented)*
-- **Changelog**: Maintain a `CHANGELOG.md` to track notable changes between releases.
+- **Changelog**: Maintain a `CHANGELOG.md` to track notable changes between releases. *(Implemented)*
 
 ## Packaging and Distribution
 

From 6a5eaad0d2f41b349b4a15c9b746c42fb811240f Mon Sep 17 00:00:00 2001
From: Bakhtier Gaibulloev <slashmsu@gmail.com>
Date: Wed, 4 Jun 2025 10:48:16 +0200
Subject: [PATCH 3/3] Add commit-msg hook to update changelog

---
 .githooks/commit-msg | 10 ++++++++++
 README.md            |  8 +++++---
 2 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100755 .githooks/commit-msg

diff --git a/.githooks/commit-msg b/.githooks/commit-msg
new file mode 100755
index 0000000..ed5d14f
--- /dev/null
+++ b/.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
diff --git a/README.md b/README.md
index e82a0d2..149ae5b 100644
--- a/README.md
+++ b/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