Action: Add workflow for automated preview deployments on latest

Author: lamATnginx

.github/workflows/previews.yml

@@ -0,0 +1,26 @@
+name: exampleSite preview
+
+on: 
+  pull_request:
+    branches:
+      - "*"
+
+jobs:
+    build:
+      runs-on: ubuntu-latest
+      steps:
+        - name: Trigger `Build and deploy` workflow in `documentation` repo
+          run: |
+            repo_owner="nginx" 
+            repo_name="documentation"  
+            event_type="trigger-preview-build" 
+            environment="preview"
+            theme_version=""
+
+            curl -L \
+            -X POST \
+            -H "Accept: application/vnd.github+json" \
+            -H "Authorization: Bearer ${{ secrets.PERSONAL_ACCESS_TOKEN }}" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/$repo_owner/$repo_name/dispatches \
+            -d "{\"event_type\": \"$event_type\", \"client_payload\": {\"environment\": \"$environment\", \"hugo_theme_override\": \"$theme_version\"}}"