[DOC] Improve Transformer documentation (#66574)
Summary:
Includes adding some typing annotations to TransformerEncoderLayer and TransformerDecoderLayer
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66574
Reviewed By: soulitzer
Differential Revision: D31654024
Pulled By: jbschlosser
fbshipit-source-id: 9026bd36541699b7205e893decf5abc4a3f0ab5e
