Add updated integration instructions (#46)
Add updated integration instructions (#46)

Summary:
Added a *much shorter* set of instructions to integrate with
the build plugin 4.0.

Pull Request resolved: https://github.com/facebookincubator/fbjni/pull/46

Test Plan: _eyes

Reviewed By: fabiomassimo

Differential Revision: D26545014

Pulled By: passy

fbshipit-source-id: 67f111e60fc193d75351b70976abb452e33bf943

facebookincubator/fbjni,facebookincubator/fbjni,facebookincubator/fbjni,facebookincubator/fbjni