add rss plugin for ci

Author: Scarvy

.github/workflows/ci.yml

@@ -25,5 +25,5 @@ jobs:
           path: ~/.cache 
           restore-keys: |
             mkdocs-material-
-      - run: pip install mkdocs-material 
+      - run: pip install mkdocs-material mkdocs-rss-plugin
       - run: mkdocs gh-deploy --force