How to register a partnership firm?

What is the procedure to register a partnership firm?

I have a startup and me along with my friend are partners.

We do not have anything in writing.

We are doing this business from last 3 months. Now we got a big project and want to register our partnership firm.

How many days it will take to register a partnership firm?

What documents we need to have for registering a partnership firm?

What is the cost of registration?