Suppressed the option to file a default issue on NVDA's Github new issue chooser page. (PR #12334) (#12334)
The default issue is just a copy of the bug issue template with introductory text suggesting it not be used.
Added a config.yml file to the Github issue config folder, which stops the option from being generated.
Left the default issue template file in place, in case some Github quirk or error allows its filing in the future.