CONTRIBUTING.md: setup, where things go, the house rules reviews catch, checks, license

CONTRIBUTING.md

@@ -0,0 +1,49 @@
+# Contributing
+
+Thanks for helping. Bugs, component requests and pull requests are all welcome.
+
+## Before you start
+
+- Try the component live at https://elygpui.com/components/ first; it may already do what you need.
+- Open an issue from a template (Bug Report, Component Request or Other) before a large change, so we agree on the shape first.
+
+## Setup
+
+- Rust 1.95 with `rustup target add wasm32-unknown-unknown`. No full Xcode needed: gpui compiles its shaders at runtime.
+- For the website: Node 24 and pnpm 11.
+- Development happens on macOS; the capture tool needs it.
+
+```sh
+cargo run --example gallery              # every chapter, light and dark
+cargo run --example gallery -- --page forms
+```
+
+## Where things go
+
+- A component lives in `src/<chapter>/`, one folder per chapter. One component, one home; anything that duplicates another points to it.
+- Its demo is a story on the chapter's page, `examples/gallery/pages/<chapter>.rs`. After adding or renaming a story, run `python3 scripts/stories.py`.
+- `TASKS.md` and `tasks/` track every component; tick its line when it lands.
+- The website is `frontend/`; its README section has the commands.
+
+## House rules
+
+`AGENTS.md` holds them all. The ones reviews catch most:
+
+- Colors, sizes, radii and shadows come from `cx.theme()`; no raw `px()` in components. Spacing uses gpui's rem helpers.
+- Every component works in light and dark, at 280px wide, by keyboard (Tab reaches it, a 1px focus ring shows, Enter and Space press it), and holds still under reduced motion.
+- Fail fast and log state changes; no silent fallbacks.
+- Files stay at or under 500 lines. Comments are one short line, and rare.
+- A new rule or dependency gets a line in `AGENTS.md`.
+
+## Checks
+
+```sh
+scripts/check.sh                         # fmt, clippy, tests, the web lint, house rules
+cd frontend && pnpm test && pnpm build && pnpm e2e   # when you touch the website
+```
+
+CI runs the same on every pull request. Fill in the pull request template: what and why, light and dark screenshots for anything that draws.
+
+## License
+
+Ely is MIT or Apache-2.0, at your option. Unless you say otherwise, what you contribute is licensed the same way.

README.md

@@ -5,7 +5,7 @@ Every component ships in light and dark. The palette is warm and quiet. Color ca
 
 Every component runs live at https://elygpui.com, compiled to WebAssembly.
 
-Status: early. `TASKS.md` tracks every component, chapter by chapter.
+Status: early. `TASKS.md` tracks every component, chapter by chapter. To help, see `CONTRIBUTING.md`.
 
 ## Use