add deploy docs workflow

.github/workflows/deploy-docs.yml

@@ -0,0 +1,14 @@
+name: deploy docs
+on:
+  push:
+    branches: [main]
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: superfly/flyctl-actions@master
+        env:
+          FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+        with:
+          args: "deploy"