Update ci.yml

addd python markdown and glightbox extensions to build job

Author: idmac75

.github/workflows/ci.yml

@@ -12,5 +12,7 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: 3.x
-      - run: pip install mkdocs-material 
+      - run: pip install mkdocs-material
+      - run: pip install pymdown-extensions
+      - run: pip install mkdocs-glightbox
       - run: mkdocs gh-deploy --force