Improve documentation

Link

https://github.com/supabase/auth/blob/master/README.md

Describe the problem

There is documentation missing in various ways. The first I noticed was with the /verify endpoint where I had to dig into the api folder to figure out which type I needed to pass. signup | recovery | invite and sms are noted, missing "email_change" and perhaps others but that's the one I ran into and had to search the api folder to figure out that it existed.

Describe the improvement

Add "email_change" and any other options for the "type" field to the documentation for the /verify route, including perhaps an example code block using it, as had been done for some of the other options.

Additional context

I just happened to come across the string as I was exploring the code and it did the job..