Missing API documentation

Description

I was trying to understand how I can customize request body validation but as far as I can tell the docs, while generally very good about describing how to use Connexion, do not appear to contain actual API documentation. In particular the section on custom validators shows how to configure what validator to use but not how to create a custom validator.

Expected behavior

Classes and methods should have browsable API documentation without the need to navigate through Connexion's code itself.

Actual behavior

No API documentation appears to exist.

Steps to reproduce

1. Visit the documentation on readthedocs
2. Look for API documentation
3. Fail to find it

Additional info:

N/A