Add deploy workflow: ping bloombilt-infra on push to master

.github/workflows/deploy.yml

@@ -0,0 +1,20 @@
+name: deploy
+
+# On push to the default branch, ping bloombilt-infra to redeploy. The infra
+# stack rebuilds this app's image and CloudFormation rolls the service.
+# docuseal's default branch is master (not main).
+on:
+  push:
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  trigger:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Ping bloombilt-infra to redeploy
+        env:
+          GH_TOKEN: ${{ secrets.BLOOMBILT_CI_TOKEN }}
+        run: gh api -X POST repos/bloombilt/bloombilt-infra/dispatches -f event_type=app-changed