Add dracula theme to deploy script

.github/workflows/deploy.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Install MkDocs
         run: |
           python -m pip install --upgrade pip
-          pip install mkdocs mkdocs-material mkdocs-git-revision-date-localized-plugin
+          pip install mkdocs mkdocs-material mkdocs-git-revision-date-localized-plugin mkdocs-dracula-theme
 
       - name: Build the MkDocs site
         run: mkdocs build