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

[Michael Catanzaro]

On Thu, Nov 17 2022 at 02:41:35 PM -0800, Ryosuke Niwa 
<rniwa at apple.com> wrote:
> 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.

Problem is, that is not very useful when the change is anything other 
than a change that fixes a bug. :)