feat: add rich documentation, sync workflow, and slim README

- Create 10 comprehensive MDX doc pages in docs/website/ (~9600 words
  total) covering installation, configuration, styling, JS API, version
  pinning, CI testing, security, self-hosting, and FAQ
- Add GitHub Action workflow to sync docs/website/*.mdx to bugdrop-web
  repo on push to main, triggering Vercel redeploy
- Slim README from 500 to 76 lines, keeping quick start and linking to
  bugdrop.dev/docs for full documentation

Author: neonwatty

.github/workflows/sync-docs.yml

@@ -0,0 +1,35 @@
+name: Sync docs to bugdrop-web
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'docs/website/**'
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout bugdrop
+        uses: actions/checkout@v4
+
+      - name: Checkout bugdrop-web
+        uses: actions/checkout@v4
+        with:
+          repository: mean-weasel/bugdrop-web
+          path: bugdrop-web
+          token: ${{ secrets.BUGDROP_WEB_TOKEN }}
+
+      - name: Sync docs
+        run: |
+          cp docs/website/*.mdx bugdrop-web/src/content/docs/
+          cd bugdrop-web
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add src/content/docs/
+          if git diff --cached --quiet; then
+            echo "No documentation changes to sync"
+          else
+            git commit -m "docs: sync documentation from bugdrop repo"
+            git push
+          fi