Update the deploy to install all the dependencies not just mkdocs.

This fixes the deploy failing that occurred after merging PR #118 (sponsor page redesign) that added the macros plugin for mkdocs.

Author: mrbiggred

.github/workflows/ci.yml

@@ -28,5 +28,5 @@ jobs:
           path: .cache
           restore-keys: |
             mkdocs-material-
-      - run: pip install mkdocs-material 
+      - run: pip install -r requirements.txt 
       - run: mkdocs gh-deploy --force