Supporting more datatypes in vertex attributes

[candronikos]

I don't see a way to use anything other than f32 at the moment and I was wondering if this was on the roadmap for a future release.

I'm happy to take a crack at it myself but would appreciate some guidance on the preferred way of doing this and other considerations.

[elliegoldstein]

Golem isn't actively developed anymore, but if you want to make a pull-request I'd be happy to review/merge it.