mkdocs workflow: pip install annotations

Author: ulido

.github/workflows/mkdocs.yaml

@@ -18,6 +18,7 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: 3.x
+      - run: pip install -e .
       - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV 
       - uses: actions/cache@v4
         with: