Operator developer guidance (#72470)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72470
Use markdown to write an upgrader guidance
ghstack-source-id: 149079223
Test Plan: CI
Reviewed By: iseeyuan, tugsbayasgalan
Differential Revision: D34054964
fbshipit-source-id: 80f907701a9d44bcd6b5c22d01a471c26669bfb0
(cherry picked from commit eaed7627f526cab932273d24002a4f8e4a92c824)
