Add docs on config

[nsheff]

for a new user unfamiliar with PEP, It's not clear what you can do with config (derived columns etc). It would be nice to get some links/explanations about subsamples and config

[nleroy917]

Tried to add this.

[sanghoonio]

I know the iframe looks kind of stupid, but what about something like this:

We can write some docs content if we take this approach

[nleroy917]

I think we should just not add something and direct users to the documentation if they are really confused. I don't like the idea of polluting the UI with "info" icons everywhere...