Trigger reusable workflow in PR workflow

Author: reakaleek

.github/workflows/pr.yml

@@ -6,6 +6,9 @@ on:
 permissions:
   contents: read
   packages: read
+  id-token: write
+  pull-requests: write
+  deployments: write
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -36,4 +39,17 @@ jobs:
       # we run our artifact directly please use the prebuild
       # elastic/docs-builder@main GitHub Action for all other repositories!
       - name: Build documentation
-        run: .artifacts/publish/docs-builder/release/docs-builder --strict
+        env:
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: .artifacts/publish/docs-builder/release/docs-builder --strict --path-prefix "/${GITHUB_REPOSITORY}/pull/${PR_NUMBER}"
+      
+      - uses: actions/upload-artifact@v4
+        with:
+          name: docs
+          path: .artifacts/docs/html
+          if-no-files-found: error
+          retention-days: 1
+
+  preview:
+    needs: build
+    uses: ./.github/workflows/preview.yml