feat: add documentation website (Docusaurus)

- 25 documentation pages covering Getting Started, User Guide, Developer Guide, and Reference
- Docusaurus with custom amber/gold theme matching the landing page branding
- GitHub Actions workflow to deploy landing page + docs to GitHub Pages
- Landing page at root, docs at /docs/ on hermes-agent.nousresearch.com
- Content extracted and restructured from existing repo docs (README, AGENTS.md, CONTRIBUTING.md, docs/)
- Auto-deploy on push to main when website/ or landingpage/ changes

.github/workflows/deploy-site.yml

@@ -0,0 +1,60 @@
+name: Deploy Site
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'website/**'
+      - 'landingpage/**'
+      - '.github/workflows/deploy-site.yml'
+  workflow_dispatch:
+
+permissions:
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deploy.outputs.page_url }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+          cache-dependency-path: website/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+        working-directory: website
+
+      - name: Build Docusaurus
+        run: npm run build
+        working-directory: website
+
+      - name: Stage deployment
+        run: |
+          mkdir -p _site/docs
+          # Landing page at root
+          cp -r landingpage/* _site/
+          # Docusaurus at /docs/
+          cp -r website/build/* _site/docs/
+          # CNAME so GitHub Pages keeps the custom domain between deploys
+          echo "hermes-agent.nousresearch.com" > _site/CNAME
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: _site
+
+      - name: Deploy to GitHub Pages
+        id: deploy
+        uses: actions/deploy-pages@v4