Hey! Me again :)

From what I've gathered from the code and from #91 it's currently not possible to load a different schema. My use case is that I want to retain a bit of interoperability between different ProseMirror editors (until we settle and migrate to one) and would like to use the original schema.

From what I've seen I think the only difference is that nib uses camelCase instead of snake_case (e.g. bulletList instead of bullet_list). I don't mind, but is there any particular reason behind it? (Just curious, doesn't matter for the issue)