Add KDocs for remove

[Jolanrensen]

Related to #811

The remove operation contains just a few overloads which differ just by how the columns should be selected (we have templates for this concept), so it should be relatively simple to get started getting used to the KDoc preprocessor with this function.

What is important to tell users that removing nested columns in column groups is supported!

A grammar DSL could be possible, showing both the - overload and the normal name