[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 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.

Michael