Command to rad init a git repo

[maninak]

The user should have the option to run a command from the palette that would rad init an already existing git repo.

• should only be shown if the workspace is a git repo AND is not already rad-initialized

Ideally

• the user specifies more details before running the command e.g. public/private repo, -no-seed, --no-seed, --default-branch
• there's a complementary command to "uninit" or "de-init" a repo, practically undoing all changes to the git repo, deleting an local rad copies from storage, etc

Notes:

• the above is a missing step for our Onboarding Flow