Reorganize: Move all skills to skills/ folder

- Created skills/ directory
- Moved 272 skills to skills/ subfolder
- Kept agents/ at root level
- Kept installation scripts and docs at root level

Repository structure:
- skills/           - All 272 skills from skills.sh
- agents/           - Agent definitions
- *.sh, *.ps1       - Installation scripts
- README.md, etc.   - Documentation

Co-Authored-By: Claude <noreply@anthropic.com>

skills/plugins/claude-hud/CONTRIBUTING.md

@@ -0,0 +1,75 @@
+# Contributing
+
+Thanks for contributing to Claude HUD. This repo is small and fast-moving, so we optimize for clarity and quick review.
+
+## How to Contribute
+
+1) Fork and clone the repo
+2) Create a branch
+3) Make your changes
+4) Run tests and update docs if needed
+5) Open a pull request
+
+## Development
+
+```bash
+npm ci
+npm run build
+npm test
+```
+
+## Tests
+
+See `TESTING.md` for the full testing strategy, fixtures, and snapshot updates.
+
+## Code Style
+
+- Keep changes focused and small.
+- Prefer tests for behavior changes.
+- Avoid introducing dependencies unless necessary.
+
+## Build Process
+
+**Important**: PRs should only modify files in `src/` — do not include changes to `dist/`.
+
+CI automatically builds and commits `dist/` after your PR is merged. This keeps PRs focused on source code and makes review easier.
+
+```
+Your PR: src/ changes only → Merge → CI builds dist/ → Committed automatically
+```
+
+## Pull Requests
+
+- Describe the problem and the fix.
+- Include tests or explain why they are not needed.
+- Link issues when relevant.
+- Only modify `src/` files — CI handles `dist/` automatically.
+
+## Releasing New Versions
+
+When shipping a new version:
+
+1. **Update version numbers** in all three files:
+   - `package.json` → `"version": "X.Y.Z"`
+   - `.claude-plugin/plugin.json` → `"version": "X.Y.Z"`
+   - `.claude-plugin/marketplace.json` → `"version": "X.Y.Z"`
+
+2. **Update CHANGELOG.md** with changes since last release
+
+3. **Commit and merge** — CI builds dist/ automatically
+
+### How Users Get Updates
+
+Claude Code plugins support updates through the `/plugin` interface:
+
+- **Update now** — Fetches latest from main branch, installs immediately
+- **Mark for update** — Stages update for later
+
+Claude Code compares the `version` field in `plugin.json` against the installed version. Bumping the version number (e.g., 0.0.1 → 0.0.2) allows users to see an update is available.
+
+### Version Strategy
+
+We use semantic versioning (`MAJOR.MINOR.PATCH`):
+- **PATCH** (0.0.x): Bug fixes, minor improvements
+- **MINOR** (0.x.0): New features, non-breaking changes
+- **MAJOR** (x.0.0): Breaking changes