Commit the result of a Github Actions job to its repository

commit-to-repo.yml

# Adapted from
# https://github.com/actions/checkout/blob/25a956c84d5dd820d28caab9f86b8d183aeeff3d/README.md#push-a-commit-using-the-built-in-token
# https://stackoverflow.com/a/8123841/822292
name: Commit the result of this Github Actions job to this repository
on: push
jobs:
  my-job:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2

        ...

      - name: Commit new and updated files back to this repository
        run: |
          git config user.name github-actions
          git config user.email github-actions@github.com
          git add .
          git diff-index --quiet HEAD || git commit -m "[skip ci] Save result of action"
          git push