Description of problem:

The implementation of custom-profiles has changed. All references to jupyterhub-custom-profiles need to be removed from the current documentation. 

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. <steps>

Actual results:

There are several occurrences of jupyterhub-custom-profiles mentioned in the documentation

Expected results:

jupyterhub-custom-profiles should not be mentioned in the documentation

Reproducibility (Always/Intermittent/Only Once):

Build Details:

Additional info: