Separate out collection / block types

[tyteen4a03]

Currently, the way TypeScript types are defined makes it hard to separate out the individual pieces (e.g. collections, blocks, schemas, etc) into their own files but still retain type checking.

It would be great if we can separate out the typings so that defining collections in their own files is easier (and I would say should be encouraged - it gets messy very quick defining everything in one config file)