Extend PR template after branching docs

[maximiliankolb]

In "foreman-documentation", there are a lot of open upstream PRs and there is typically a lot of cherry-picking to release branches. When we push the new release branch to foreman-documantation, we should immediately add this as a friendly reminder to a) users opening new PRs and b) maintains that cherry-pick PRs to the PR template.

cc @Griffin-Sullivan

Related to theforeman/foreman-documentation#2821 and theforeman/foreman-documentation#2820

[Griffin-Sullivan]

In the line above it says to do this as part of the foreman-documentation branching process here: https://github.com/theforeman/foreman-documentation#branching-new-release. You can see I made that change in https://github.com/theforeman/foreman-documentation/pull/2803/files. I guess part of the reason you're commenting this is because we don't always do a good job of closing the branching PR before starting the release updates so it gets added into a mega PR.

[maximiliankolb]

I believe we were too slow to review it. But because there's a lot of cherry-picking in foreman-documentation, I believe it makes sense to add a single line "cherry-pick to NEW FOREMAN RELEASE?" to the PR template immediately after branching.

[ekohl]

It's already part of theforeman/foreman-documentation@fd460a0. Why does it need to be here too?

The idea is that we don't duplicate exact branching instructions here, but rather refer to the authoritative source, which in this case is foreman-documentation.

For reference, https://github.com/theforeman/jenkins-jobs/blob/master/branch-foreman is a script where there's more automated.

Another design idea behind this procedure is that the one executing it constantly reflects on the process and improves where needed. So if foreman-documentation is painful, it's good to automate more.

[ekohl]

@maximiliankolb given it's already part of the foreman-documentation steps which are referred to, can we close this?