You can't check if "CI is passing" until you create a PR, because for most people Buildkite will only run the build when a PR is created (It will run on branch push only if you push to a branch of the `rails/rails` repo, which only people with write access can do.). So we shouldn't tell people to wait for CI to pass before submitting a PR.
This PR just tweaks the CI template to explain this in a comment so that people know to check back once CI has actually run.
I've noticed a few PRs made since the latest template update, that have said things like "this PR was created because of #ISSUE" or things along those lines. It seems like people are reading the template and following its advice! But Github requires a specific syntax to auto-close an issue, so we may as well encourage people to use that to save everyone a bit of time. So in this PR I've added a comment to the template explaining that.
I think no one is reading this because I've seen an increase in draft
PRs. To fix that I've moved the draft statement to the top. I also think
the number of check boxes is a lot and isn't resulting in better PRs
because the length means they are not being read. I removed ones that I
think are repetitive or unhelpful. I wish I could A/B test this...
The major change is to add checklist so that it's easier to be read
than comments.
Also, `Summary` is not clear about what should be written, so here
it's changed to `Motivation` and `Detail`.
Finally, it clearly says they can discard this template if they need to.
