How do I co-develop a game using C2

As the title.

Before buying a license, I just want to know the how to co-develop, or does C2 support co-developing?

Each person will need a licensed copy if you plan on using license features (families etc)

It doesn't support co-development.

But it doesn't need to as this is probably the better way to co-develop anyway : Tutorial: Collaborate using Github

It's the same as SVN I think.

But if my partner and I is changing the project at the same time, and I upload the project first, it's no way to merge our changes, right?

Nope...

What has helped me in the past if you break project up into pieces and each work on his/her sections, then put together at end.