We should make our config names more package specific

[mmcdermott]

E.g., add "_"s in front of them. This won't affect our code's interface, but if someone ever tries to import one of our provided configs as a default in hydra, this will make it harder to accidentally suffer from name collision which causes hydra to go into an infinite recursion loop.

[mmcdermott]

Relevant issues with more discussion: facebookresearch/hydra#1828, justin13601/ACES#122