chore: migrate site to Zensical

.github/workflows/github-pages.yml

@@ -28,7 +28,7 @@ jobs:
         run: uv sync --locked --group docs
 
       - name: Build
-        run: uv run --group docs mkdocs build
+        run: uv run --group docs zensical build
 
       - name: Write CNAME
         if: ${{ vars.PAGES_CNAME != '' }}