[REQ] Gist-support

[LeibelRyan]

Please add config support for "https://gist.github.com/" while we host to heroku...

Like this repo: https://github.com/SlamDevs/slam-mirrorbot/wiki/Deploying-slam-mirrorbot-on-Heroku-with-Github-Workflows

CONFIG_FILE_URL

[GiorgioBrux]

What's the benefit of this? If you want to automatically update your heroku build (which is something you probably shouldn't do because breaking changes can happen) just fork and then autodeploy from there, using something like pull to keep the fork up-to-date.