Link Github account

[guacamole]

Is your feature request related to a problem? Please describe.
Not Necessarily
The user can opt in to sign-in with github during their first time interacting with OpenRegsitry
It would be better if user can still have an option to connect their Github after they have signed up with basic auth

Describe the solution you'd like
Connect Github functionality

Describe alternatives you've considered
NA

Additional context
there should be a Connect Github button on frontend which should update user data in db if the user chooses to user their github username and email