[webkit-dev] Update commit log template to add placeholder for explanation of why a patch fixes a bug

[Ryosuke Niwa]

> On Nov 17, 2022, at 2:37 PM, Michael Catanzaro via webkit-dev <webkit-dev at lists.webkit.org> wrote:
> 
> On Thu, Nov 17 2022 at 12:23:54 PM -0800, David Kilzer via webkit-dev <webkit-dev at lists.webkit.org> wrote:
>> Any feedback on this change?
> 
> We could alternatively say "Explanation of this change (OOPS!)" or "Explanation of this commit (OOPS!)" to be a little more general.

That’s strictly worse than “explain why this fixes the bug”.

We don’t want a description of what PR is; that’s obvious from diff. We want a description of why that PR fixes the bug.

- R. Niwa