Write CONTRIBUTING guide (#49)

Co-authored-by: Yan Thomas <61414485+Yan-Thomas@users.noreply.github.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 00000000..69d30d3f
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,98 @@
+# Contributor Manual
+
+We welcome contributions of any size and contributors of any skill level.
+As an open source project, we believe in giving back to our contributors.
+We are happy to help with guidance on PRs, technical writing, and turning any feature idea into a reality.
+
+> **Tip for new contributors:**
+> Take a look at [GitHub's Docs](https://docs.github.com/en/get-started/quickstart/hello-world) for helpful information on working with GitHub.
+
+This document is an active work in progress — like Starlight itself! Feel free to join us in [the Astro Discord server][discord] to join the discussion. Look for the `#starlight` channel and say “Hi!” when you arrive.
+
+## Types of contributions
+
+There are lots of ways to contribute to Starlight.
+
+Maintaining Starlight requires writing Astro code, as well as addressing accessibility, styling, and UX concerns.
+This repository also contains the code for the Starlight docs website.
+Help writing docs, catching typos and errors, as well as translating docs into other languages is always welcome.
+
+You can also get involved by leaving feedback on [issues][issues] or reviewing [pull requests][pulls] by other contributors.
+
+We encourage you to:
+
+- [**Open an issue**][new-issue] to let us know of bugs in Starlight, documentation you found unclear, or other issues you run into.
+
+- [**Look at existing issues**][issues] (especially those labelled [“good first issue”][gfi]) to find ways to contribute.
+
+- **Make a pull request (PR)** to address an open issue or to fix obvious problems.
+  Read more about [making a PR in GitHub’s docs][pr-docs]
+
+- [**Review existing PRs**][pulls] to help us merge contributions sooner.
+
+## About this repo
+
+This repo is a “monorepo,” meaning it contains several projects in one. It contains the Starlight docs site in [`docs/`](./docs/) and the packages that make up Starlight in [`packages/`](./packages/).
+
+### Setting up a development environment
+
+**Prerequisites:** Developing Starlight requires [Node.js](https://nodejs.org/en) and [pnpm](https://pnpm.io/). Make sure you have these installed before following these steps.
+
+1. **Fork Starlight** to your personal GitHub account by clicking <kbd>Fork</kbd> on the [main Starlight repo page][sl].
+
+2. **Clone your fork** of Starlight to your computer. Replace `YOUR-USERNAME` in the command below with your GitHub username to clone in a Terminal:
+
+   ```sh
+   git clone https://github.com/YOUR-USERNAME/starlight.git
+   ```
+
+3. **Change directory** to the cloned repo:
+
+   ```sh
+   cd starlight
+   ```
+
+4. **Install dependencies** with `pnpm`:
+
+   ```sh
+   pnpm i
+   ```
+
+### Testing changes while you work
+
+Run the Astro dev server on the docs site to see how changes you make impact a project using Starlight.
+
+To do this, move into the `docs/` directory from the root of the repo and then run `pnpm dev`:
+
+```sh
+cd docs
+pnpm dev
+```
+
+You should then be able to open <http://localhost:3000> and see your changes.
+
+### Understanding Starlight
+
+- Starlight is built as an Astro integration.
+  Read the [Astro Integration API docs][api-docs] to learn more about how integrations work.
+
+  The Starlight integration is exported from [`packages/starlight/index.ts`](./packages/starlight/index.ts).
+  It sets up Starlight’s routing logic, parses user config, and adds configuration to a Starlight user’s Astro project.
+
+- Most pages in a Starlight project are built using a single [`packages/starlight/index.astro`](./packages/starlight/index.astro) route.
+  If you’ve worked on an Astro site before, much of this should look familiar: it’s an Astro component and uses a number of other components to build a page based on user content.
+
+- Starlight consumes a user’s content from the `'docs'` [content collection](https://docs.astro.build/en/guides/content-collections/).
+  This allows us to specify the permissible frontmatter via [a Starlight-specific schema](./packages/starlight/schema.ts) and get predictable data while providing clear error messages if a user sets invalid frontmatter in a page.
+
+- Components that require JavaScript for their functionality are all written without a UI framework, most often as custom elements.
+  This helps keep Starlight lightweight and makes it easier for a user to choose to add components from a framework of their choice to their project.
+
+[discord]: https://astro.build/chat
+[issues]: https://github.com/withastro/starlight/issues
+[sl]: https://github.com/withastro/starlight/pulls
+[pulls]: https://github.com/withastro/starlight/pulls
+[new-issue]: https://github.com/withastro/starlight/issues/new/choose
+[pr-docs]: https://docs.github.com/en/get-started/quickstart/contributing-to-projects#making-a-pull-request
+[gfi]: https://github.com/withastro/starlight/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22+
+[api-docs]: https://docs.astro.build/en/reference/integrations-reference/