Add WordPress.org deploy workflow

When a GitHub release is published, download the plugin zip
from the release and deploy it to WordPress.org via SVN.

Author: JanJakes

.github/workflows/release-wporg.yml

@@ -0,0 +1,30 @@
+name: Deploy to WordPress.org
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  deploy:
+    name: Deploy plugin to WordPress.org
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download plugin zip from release
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          RELEASE_TAG: ${{ github.event.release.tag_name }}
+        run: |
+          gh release download "$RELEASE_TAG" \
+            --repo "${{ github.repository }}" \
+            --pattern "sqlite-database-integration.zip" \
+            --dir .
+          unzip sqlite-database-integration.zip
+
+      - name: Deploy to WordPress.org
+        uses: 10up/action-wordpress-plugin-deploy@v2
+        env:
+          SVN_USERNAME: ${{ secrets.SVN_USERNAME }}
+          SVN_PASSWORD: ${{ secrets.SVN_PASSWORD }}
+          SLUG: sqlite-database-integration
+          BUILD_DIR: sqlite-database-integration