docs(readme): add example about writing the changelog (#13)

README.md

@@ -101,6 +101,41 @@ jobs:
           body: ${{ needs.changelog.outputs.release_body }}
 ```
 
+#### Committing the changelog
+
+You can use this action as follows if you want to generate a changelog and commit it to the repository:
+
+```yml
+jobs:
+  changelog:
+    name: Generate changelog
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Generate a changelog
+        uses: orhun/git-cliff-action@v2
+        with:
+          config: cliff.toml
+          args: --verbose
+        env:
+          OUTPUT: CHANGELOG.md
+
+      - name: Commit
+        run: |
+          git config user.name 'github-actions[bot]'
+          git config user.email 'github-actions[bot]@users.noreply.github.com'
+          set +e
+          git add CHANGELOG.md
+          git commit -m "Update changelog"
+          git push https://${{ secrets.GITHUB_TOKEN }}@github.com/${GITHUB_REPOSITORY}.git <branch>
+```
+
+Please note that you need to change the `<branch>` to the branch name that you want to push.
+
 ## Credits
 
 This action is based on [lycheeverse/lychee-action](https://github.com/lycheeverse/lychee-action) and uses [git-cliff](https://github.com/orhun/git-cliff).