Update PR description instead of making a comment

[rehanvdm]

Will it be possible to post to the PR description instead of commenting on the PR?

This will reduce noise, because GitHub notifies for every comment created on a PR. I am not sure if the PR description length will be the limiting factor here. If it does, maybe post to the PR description first, but if it is too long, truncate and create the rest as comments.

[corymhall]

Yeah I think this should be possible. I'll probably add a property you can configure for where you want the diff to go.