Update README.md

Author: pascalgn

README.md

@@ -56,7 +56,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: automerge
-        uses: "pascalgn/automerge-action@v0.12.0"
+        uses: "pascalgn/automerge-action@v0.13.0"
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
 ```