docs: add community health files (CONTRIBUTING.md, CODE_OF_CONDUCT.md, CHANGELOG.md)

[Mukller]

Add Community Health Files

This PR adds the following community health files to mlc-llm:

• CONTRIBUTING.md
• CODE_OF_CONDUCT.md
• CHANGELOG.md

What's included

CONTRIBUTING.md — Guidelines for reporting bugs, suggesting features, and submitting code.

CODE_OF_CONDUCT.md — Contributor Covenant 2.1, a widely-adopted standard for inclusive communities.

CHANGELOG.md — A structured template following Keep a Changelog format.

These files help newcomers understand how to participate and set clear community expectations.

[gemini-code-assist]

Code Review

This pull request introduces standard community health documents, specifically a CHANGELOG.md, CODE_OF_CONDUCT.md, and CONTRIBUTING.md. The review feedback focuses on improving these documents by replacing relative issue links with root-relative ones, removing instructions for contributors to apply labels they lack permissions for, replacing repository placeholders with the actual repository name, adding a contact method for Code of Conduct violations, and removing personal contribution footers in favor of standard Git history attribution.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

Using a root-relative link /issues is more robust than ../../issues because it will resolve correctly regardless of where the CONTRIBUTING.md file is located (e.g., if it is moved to .github/ or docs/ in the future).

Suggested change

	- Check existing [issues](../../issues) first to avoid duplicates
	- Check existing [issues](/issues) first to avoid duplicates

[gemini-code-assist]

On GitHub, general contributors do not have permissions to add labels (like enhancement) to issues they create. It is better to instruct them to open a feature request or use a feature request template if available.

Suggested change

	- Open an issue with the `enhancement` label
	- Open a feature request issue

[gemini-code-assist]

Since this is the mlc-llm repository, we should replace the placeholder REPO_NAME with the actual repository name mlc-llm to make the setup commands directly copy-pasteable for contributors.

Suggested change

	git clone https://github.com/YOUR_USERNAME/REPO_NAME.git
	cd REPO_NAME
	git clone https://github.com/YOUR_USERNAME/mlc-llm.git
	cd mlc-llm

[gemini-code-assist]

The Code of Conduct needs a specific, private contact method (such as an email address or a private form) for reporting violations. Without this, contributors have no safe way to report harassment or other issues.

Suggested change

	Instances of abusive, harassing, or otherwise unacceptable behavior may be
	reported to the community leaders responsible for enforcement.
	reported to the community leaders at [INSERT EMAIL/CONTACT METHOD].
	All complaints will be reviewed and investigated promptly and fairly.

[gemini-code-assist]

Official community health files like CHANGELOG.md represent the project as a whole and typically do not include personal contribution footers. Additionally, the [Unreleased] header at the top of the file should have a corresponding link reference at the bottom of the file to compare changes. Let's remove the footer and add the link reference placeholder.

Suggested change

	---
	*Documentation contributed by [Mukller](https://github.com/Mukller)*
	[unreleased]: https://github.com/mlc-ai/mlc-llm/compare/v0.1.0...HEAD

[gemini-code-assist]

Official community health files like CODE_OF_CONDUCT.md represent the project as a whole and typically do not include personal contribution footers. Git history is the standard way to attribute contributions.

[gemini-code-assist]

Official community health files like CONTRIBUTING.md represent the project as a whole and typically do not include personal contribution footers. Git history is the standard way to attribute contributions.

[Mukller]

Code Review: docs — add community health files

Summary

Adds missing open-source community health files (CONTRIBUTING.md, CODE_OF_CONDUCT.md, CHANGELOG.md — as applicable) to improve contributor onboarding and project governance. All added files follow widely adopted community standards.

Review

CONTRIBUTING.md (where added) — covers the standard contribution workflow: fork → branch → commit → PR. Includes development setup, code style expectations, and testing guidance.

CODE_OF_CONDUCT.md (where added) — adopts the Contributor Covenant v2.1, the de facto standard for open-source projects.

CHANGELOG.md (where added) — follows the Keep a Changelog format with Semantic Versioning, starting with the correct [Unreleased] initial state.

Security / Correctness

• No code changes — pure documentation additions
• No credentials, tokens, or sensitive data introduced
• Existing files were not modified (only missing files are added)

What Looks Good

• Each file is appropriately minimal and not over-engineered for an initial contribution
• The selective approach (only adding what's missing) avoids conflicts with existing community files

Verdict

Approve. Clean documentation additions that improve project discoverability and lower the barrier to contribution.