Please document cognitect.rebl/submit or similar API call

[jafingerhut]

The README mentions "and accepts values to inspect via an API call", but a search for the word submit using Github's search within this project shows it does not occur anywhere in the code or wiki. The word "submit" is mentioned in 2 issues, but I even if those were about the API call (I don't think they are), it would be nice to have some "official" documentation for it, and perhaps even a doc string.