Add new action for rebuilding imports

@balhoff set up a jenkins job for GO that will rebuild extracted import modules and make a PR.

https://gist.github.com/balhoff/6c0d434b1601de4d4006bff76b858ac1

On slack he mentioned it would be possible to translate this to a github action.

He also set up a github action for doing a reasoned diff as a PR:
https://github.com/geneontology/go-ontology/blob/master/.github/workflows/inference_diff.yml

It would be great to have both actions available in the template

I am not sure if there are other considerations

- should it be throttled, e.g. certain kinds of changes could generate very large markdown files
- we only want the import diff to run under some circumstances

See also

* #335

Which is about having a github action to make a draft release