Automation to notify PR authors that their PR has a merge conflict

[Piedone]

Is your feature request related to a problem? Please describe.

When a PR has merge conflicts, the reviewer has to point that out if the author doesn't check back. Otherwise, the author wouldn't know that since they opened it, they PR got a merge conflict.

Describe the solution you'd like

Automate this. Similar to what Lombiq's validate-pull-request workflows does (but with pull_request_target), we could use eps1lon/actions-label-merge-conflict to label conflicting PRs, and add a comment under them. See example.

Describe alternatives you've considered

Perhaps there are other usable automation for this but the mentioned action works well.

[hishamco]

Go for it