Refactor docs to be deployed as a static content

.github/workflows/docs.yml

@@ -10,7 +10,7 @@ jobs:
         with:
           submodules: "recursive"
       - name: Set up Python
-        uses: actions/setup-python@v1
+        uses: actions/setup-python@v2
         with:
           python-version: 3.7
       - name: Install dependencies