[hax party] gh support for onboarding (plus fixing some old bugs)

[winstonwumbo]

New Features

• Added support for the gh cli utility! This makes the hax party workflow much smoother, allowing HAX to fork directly from the CLI. Users don't need to keep going back to the browser to fork each and every repo.
• Wrote more onboarding documentation for new HAXxers, providing direction to dev dependencies and hax party
• Fixed a bug with passing the git config user.name author into hax party
• Fixed a bug with checking SSH keys through exec() process (stderr would automatically close the whole process if it's not wrapped in a try-catch)

Related Issue(s)

• if you've never authed to github locally with keys, it won't let you do anything! issues#2352
• [create] Add gh (GitHub cli) support to hax party issues#2459

[btopro]

Sick