Document naming strategies

[jrheard]

I just found out that naming strategies exist after spending a good chunk of time diagnosing enum-value-name-related issues in my project and then reading through the Issues section of this github project. Between reading the actual source code of the library and cross-referencing against the discussion on https://github.com/flatland/clojure-protobuf/issues/27 , I think I'll be able to figure out what's going on and how to take advantage of naming strategies, but this definitely seems like the sort of thing that should be written down somewhere, preferably in the README or wherever else this project is documented; a Google search for "clojure protobuf naming strategy" doesn't turn up anything at all.

(also thanks for your work on this project, I'm really glad you guys did all this heavy lifting so I won't have to! :)