GitHub App supported as a provider via API setup

Description of the feature request

POST apps/register has a provider parameter with available values: github, bitbucket, gitlab, gitlab-self-hosted or custom. I’d appreciate adding support for a GitHub App.

Use case / for what or how I would use it

I want to setup new projects in a fully automated way. For now, in the middle of setup I have to go to the UI to integrate with GitHub and then continue with my setup scripts.
Note: I’d rather not use SSH keys.