add github actions, fix readme for pypi

.github/workflows/sphinx-build.yml

@@ -0,0 +1,26 @@
+name: "Documentation Deploy"
+
+on: 
+  push:
+    tags:
+      - "*"
+
+jobs:
+  docs:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create the new documentation
+      uses: ammaraskar/sphinx-action@master
+      with:
+        pre-build-command: "python -m pip .[docs]"
+        docs-folder: "docs/"
+
+    - name: Deploy
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        #deploy_key: ${{ secrets.DEPLOY_PRIVATE_KEY }}
+        publish_dir: ./docs/build/html
+        allow_empty_commit: true