Add an eyes layer

We currently have 4 layers; background, headphones, type and smoke.

I propose that we add an eyes layer, the benefits I see in this are:

• Raise the possible combinations for uniqueness to avoid visual duplicates
• I think the idea of building the art layers as a DAO could be a fun experience that I haven't seen done before.

This proposal isn't to decide what the eyes traits would be at all, it's just to decide it's something we want to do and then other future proposals and discussions can be about what that would look like (IMO it doesn't necessarily have to be all and only the eyes layers in the OG mfers collection, we could for example add one nounish eyes, maybe create new ones or not...).