Task: Document how to contribute resources

[kaitj]

Description

We have a contributing guide already for the code, we should also include some sort of documentation (maybe in the README?) for how to contribute resources (annotations, atlases, transforms, etc.)

Tasks

• Add documentation for contributing resources

Freeform Notes

Things to consider:

• open or requires a DUA?
• references
• any notes, caveats, etc.
• direct uri to source or a file
  • if a file, probably need some way to contact or share so we can upload