Where do I create requests for improving existing mdn articles?

[DanKaplanSES]

Here's the context: I'd like to create an issue re: the nth-child and nth-of-type pages. Specifically, I'd like to propose they mention and include examples of how nth-child and nth-of-type differ.

When I tried to create a new issue I was presented with this:

I don't know which one I should use to propose my suggestion:

1. 
   Should I use this one? It is a content issue.
2. 
   This one obviously doesn't fit.
3. 
   I think this is saying that it should only be used by clicking a link from a rendered MDN page? If so, maybe it could be more explicit about that, mentioning it's for automated purposes only?
4. 
   This is a "Content" request, so it fits, but it fits as much as the 1st choice.

[hamishwillee]

Please use the first one - "Content Issue".

@schalkneethling FYI. 3 and 4 above perhaps need a little clarification.