docs: faq section + post-join filter question

[vbarua]

No description provided.

[jacques-n]

I like it but I also think we need to avoid adding more top-level stuff. We already have too many. Is there way we can have either drop-down navs or left hand navs with this theme? I can't remember but I think there is.

[EpsilonPrime]

I agree that we have too many top level items (11). I was looking to spend more time on the website but I already have 4 pending documentation updates. I'd lean towards getting this in and fixing the navigation later.

[jacques-n]

I'm okay with this going in but we should also work on cleaning things up at the nav level.