Fix triplet margin loss and reciprocal docs (#51650)
Summary:
Reciprocal: the note should be placed after the formula
Triplet-margin-loss (before):
After:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51650
Reviewed By: izdeby
Differential Revision: D26314151
Pulled By: soulitzer
fbshipit-source-id: d7574e64e96a41a515231ba7e1008de8b2f292aa
