Defaulting to a new branch doesn't conform to standard practices. It might be better to have the script display the list of switches when run by itself. Maybe add a -n switch to accomplish the current functionality of the script run by itself.

[JoeKlemmer]

[cosmicwanderer7]

What about adding two new flags
-nb Create a repository without any branch.
-db prompts user to Specify the name of the default branch.