[docs] multi_head_attention_forward no-batch dim support (#70590)
Summary:
no batch dim support added in https://github.com/pytorch/pytorch/issues/67176
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70590
Reviewed By: VitalyFedyunin
Differential Revision: D33405283
Pulled By: jbschlosser
fbshipit-source-id: 86217d7d540184fd12f3a9096605d2b1e9aa313e
