Is your feature request related to a problem? Please describe:
Currently, whenever sigs.yaml is updated, sig-list.md (which is generated from sigs.yaml needs to get updated by calling:

make generate

Describe the solution you'd like:
A way that tells the user that they need to update sig-list.md by running the above command before the merge is completed.

Easiest might be a presubmit job that calls the target and checks whether the git state is clean.

Describe alternatives you've considered:
Variants of that might be:

• a postsubmit that is executed after changes to sigs.yaml or
• a periodic
  either way they call the target and create a pull request afterwards.

Additional context:

• example of an existing postsubmit for community sigs.yaml

/good-first-issue