docs: Add example of actions/labeler (#331)

#326

Author: peaceiris

README.md

@@ -260,7 +260,23 @@ Default is `${{ github.token }}`
 >
 > When you use the repository's `GITHUB_TOKEN` to perform tasks on behalf of the GitHub Actions app, events triggered by the `GITHUB_TOKEN` will not create a new workflow run. This prevents you from accidentally creating recursive workflow runs. For example, if a workflow run pushes code using the repository's `GITHUB_TOKEN`, a new workflow will not run even when the repository contains a workflow configured to run when push events occur.
 
-You need to provide a personal access token to an auto label GitHub Actions or GitHub Bot like `actions/labeler`.
+You need to provide a personal access token to an auto label GitHub Actions or GitHub Bot like [actions/labeler](https://github.com/actions/labeler).
+
+```yaml
+# .github/workflows/labeler.yml
+name: "Pull Request Labeler"
+
+on:
+  - pull_request_target
+
+jobs:
+  triage:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/labeler@v3
+      with:
+        repo-token: "${{ secrets.GH_PAT }}"
+```
 
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