Wconstab/doc codegen (#74850)
Summary:
Add basic docs to the lazy codegen utility
cc JackCaoG
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74850
Reviewed By: shunting314
Differential Revision: D35418039
Pulled By: wconstab
fbshipit-source-id: bfc16e42b2afcff8301f2bcc053dc911baad2241
(cherry picked from commit 479b3f5cf18d12d8e8dca661e31a1fab763c98dc)
