chore: add contributing guide

[skip ci]

.github/CONTRIBUTING.md

@@ -0,0 +1,110 @@
+# Contribute to Hextra
+
+👋 Thank you for being interested in contributing to Hextra! As an open source project, we welcome contributions of many forms including bug reports, feature requests, documentation improvements, and code contributions.
+
+<!-- omit in toc -->
+## Table of Contents
+
+- [Guidelines](#guidelines)
+  - [Contributing Code](#contributing-code)
+  - [Contributing Documentation](#contributing-documentation)
+  - [💬 GitHub Discussions](#-github-discussions)
+  - [GitHub Issues](#github-issues)
+- [Development](#development)
+  - [Local development setup](#local-development-setup)
+  - [Project structure](#project-structure)
+  - [Start the development server](#start-the-development-server)
+  - [Compile the styles](#compile-the-styles)
+
+
+## Guidelines
+
+### Contributing Code
+
+To contribute, please follow the ["Fork and Pull Request"][fork and pull] workflow：
+
+Fork the repository, make your changes, and then submit a pull request.
+Please make sure to include a description of the changes you made and why you made them.
+Use [Conventional Commits][conventional commits] message to make it easier to understand the changes you made.
+
+### Contributing Documentation
+
+Similar to contributing code, you can also contribute to the documentation by submitting a pull request.
+
+The documentation site is located in the [`exampleSite`](../exampleSite/) folder.
+You can make changes to the documentation and create a pull request. A preview of the new documentation will be automatically generated and displayed in the pull request comment via [Netlify][netlify deploy preview].
+
+### 💬 GitHub Discussions
+
+We’re using [Discussions][discussions] as a place to connect with other members using Hextra:
+
+- Ask questions you’re wondering about.
+- Share ideas.
+- Engage with other users.
+
+### GitHub Issues
+
+If you find a bug or have a feature request, please [open an issue][issues].
+
+Please make sure to include a description of the bug or feature you are requesting. If you are reporting a bug, please include steps to reproduce the bug.
+
+We recommend that you search existing [issues][issues] or discussions before opening a new one to prevent duplicates.
+
+## Development
+
+> **Note**
+> You can start developing on [GitHub Codespaces][open in codespaces] or use [devcontainer][devcontainer] locally without installing any dependencies.
+
+### Local development setup
+
+- [Hugo][hugo] >= v0.115.0 (extended version)
+- [Node.js][nodejs]
+- [Go][go]
+
+Install dependencies:
+
+```bash
+npm i
+```
+
+### Project structure
+
+- [`assets`](../assets/): CSS styles and JavaScript files.
+- [`data`](../data/): The theme data files. Now only contains the `icons.yaml` file.
+- [`exampleSite`](../exampleSite/): The documentation site for the theme.
+- [`i18n`](../i18n/): The theme translation files.
+- [`layouts`](../layouts/): The theme layouts.
+- [`static`](../static/): The static files for the theme. For example, the favicon and the site logo.
+
+Please refer to the [Hugo documentation][hugo] for more information.
+
+### Start the development server
+
+```bash
+npm run dev:theme
+```
+
+It will start the Hugo server on `http://localhost:1313/` for the `exampleSite` content.
+
+### Compile the styles
+
+For development preview, we compile the Tailwind CSS styles on the fly. But for production, we need to compile the styles first.
+
+```bash
+npm run build:css
+```
+
+It will compile the Tailwind CSS styles and generate the `assets/css/compiled/main.css` file.
+
+<!--links-->
+
+[fork and pull]: https://docs.github.com/en/get-started/quickstart/contributing-to-projects
+[conventional commits]: https://www.conventionalcommits.org
+[issues]: https://github.com/imfing/hextra/issues
+[discussions]: https://github.com/imfing/hextra/discussions
+[nodejs]: https://nodejs.org/en/
+[hugo]: https://gohugo.io/
+[go]: https://golang.org/doc/install
+[devcontainer]: https://code.visualstudio.com/docs/devcontainers/containers
+[open in codespaces]: https://codespaces.new/imfing/hextra
+[netlify deploy preview]: https://docs.netlify.com/site-deploys/deploy-previews/

.vscode/settings.json

@@ -1,4 +1,5 @@
 {
   "editor.tabSize": 2,
-  "css.customData": [".vscode/tailwind.json"]
+  "css.customData": [".vscode/tailwind.json"],
+  "markdown.extension.toc.levels": "2..6"
 }

README.md

@@ -31,13 +31,16 @@ Using the [Hextra Starter Template](https://github.com/imfing/hextra-starter-tem
 
 The template repository also includes a [GitHub Actions workflow](https://docs.github.com/en/pages/getting-started-with-github-pages/configuring-a-publishing-source-for-your-github-pages-site#publishing-with-a-custom-github-actions-workflow) for deploying your website to GitHub Pages.
 
+<img alt="Hextra Starter Template" src="https://user-images.githubusercontent.com/5097752/263551418-c403b9a9-a76c-47a6-8466-513d772ef0b7.jpg" width=600/>
+
 ### Usage
 
 Refer to the [documentation](https://imfing.github.io/hextra/docs) for more information.
 
 ## Contributing
 
-This project is actively under development. Contributions are welcome!
+Contributions are welcome!
+Check out the [contributing guide](.github/CONTRIBUTING.md) to get started.
 
 ## License