The PR template includes an item for a warning that is automatically
shown once (and once and for all) by the Github UI. In the previous
review of the changes to the pull request template, Ivan agreed that
this was redundant, so it seems there's no point in keeping it in the
pull request template itself.
This patch adds a new checkbox to ensure the user has read the `CONTRIBUTING.md` file, notably the Pull requests, Commit message format, and AI policy Sections.
Signed-off-by: Ivan Enderlin <ivan@mnt.io>