Custom achievements as a part of themes/careers

[Sygenysis]

I don't know if this is already a thing, or already possible, shame on me for not looking into it, etc., etc. That being said, this isn't really a big thing, just kind of a silly idea.

I was just wondering if custom achievements would be a potential/already do-able thing for the game. If there's already a system of easily add achievements or one could be created, I think that it would be interesting to incorporate into custom themes or with certain careers, or something.

I'm not a "good ideas" or a "decent articulation" kind of guy, so I can clarify if necessary.

Thanks in advance.