message: scaffolder: add example diff in fetch:template migration docs
diff: @@ -31,6 +31,18 @@ allow most templates built for `fetch:cookiecutter` to work without any changes.
  2. Set `cookiecutterCompat` to `true` in the `fetch:template` step input in
  `template.yaml`.
  +```diff
  + steps:
  + - id: fetch-base
  + name: Fetch Base
  +- action: fetch:cookiecutter
  ++ action: fetch:template
  + input:
  + url: ./skeleton
  ++ cookiecutterCompat: true
  + values:
  +```
  +
  #### Manual migration
  If you prefer, you can manually migrate your templates to avoid the need for
  