add github workflow for mkdocs

.github/workflows/docs.yml

@@ -0,0 +1,20 @@
+name: Deploy docs to GitHub Pages
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    name: Deploy docs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout main
+        uses: actions/checkout@v2
+
+      - name: Deploy MkDocs
+        uses: mhausenblas/mkdocs-deploy-gh-pages@master
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          REQUIREMENTS: ./requirements.docs.txt

requirements.docs.txt

@@ -0,0 +1 @@
+mkdocs-material==9.5.3