Describe the feature or problem you’d like to solve

I like to chain pull requests, which is very nice when, for example, you want to merge dependencies updates, and then stack fixes for these for updates on top, having each middle branch checked, before they all lend into master.

Unfortunately, in these cases creating pull requests with gh pr is quite annoying, because it cannot auto-fill the title and message. There is --fill and --fill-first, but they aren't useful, because --fill won't provide a useful message, and the first commit will be first merged PR.

Proposed solution

I think having --fill-from=<commit> and --fill-latest arguments will be useful. With --fill-from, CLI would automatically pick the title and message using a specific commit, whereas --fill-latest would use the message from the latest commit.

Additional context

N/A