docs: add README, CONTRIBUTING, and MIT LICENCE

- Rewrite README with project overview, structure, and script reference
- Add CONTRIBUTING guide with development workflow and coding standards
- Add MIT LICENCE

CONTRIBUTING.md

@@ -0,0 +1,50 @@
+# Contributing
+
+Thank you for considering contributing to this project.
+
+## Getting Started
+
+1. Fork the repository and clone it locally
+2. Install dependencies: `pnpm install`
+3. Create a branch for your changes: `git switch -c feature/my-change`
+4. Make your changes and ensure they pass checks
+
+## Development Workflow
+
+Before submitting a pull request, please verify:
+
+```sh
+pnpm type-check      # TypeScript type checking
+pnpm lint            # ESLint and oxlint
+pnpm test:unit:run   # Unit tests
+pnpm build           # Production build
+```
+
+## Coding Standards
+
+- Write all user-facing text in **British English**
+- Use the Composition API with `<script setup>` for Vue components
+- Format code with Prettier before committing: `pnpm format`
+- Follow existing patterns in the codebase for naming and structure
+
+## Commit Messages
+
+This project follows semantic commit conventions:
+
+```
+<type>(<scope>): <subject>
+```
+
+Types: `feat`, `fix`, `docs`, `style`, `refactor`, `test`, `chore`
+
+Keep the subject line under 50 characters and use imperative mood ("add" not "added").
+
+## Pull Requests
+
+- Keep changes focused — one feature or fix per pull request
+- Update or add tests when changing functionality
+- Ensure the CI pipeline passes before requesting review
+
+## Questions
+
+Open an issue for questions, bug reports, or feature requests.