Added GitHub Action

.github/workflows/deploy-theme.yml

@@ -0,0 +1,15 @@
+name: Deploy Theme
+on:
+  push:
+    branches:
+      - master
+jobs:
+  deploy:
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@master
+      - name: Deploy Ghost Theme
+        uses: TryGhost/action-deploy-theme@v1.2.0
+        with:
+          api-url: ${{ secrets.GHOST_ADMIN_API_URL }}
+          api-key: ${{ secrets.GHOST_ADMIN_API_KEY }}