LSTM's -> LSTMs in equence_models_tutorial.py docs (#1136)

Co-authored-by: Brian Johnson <[email protected]>

Author: adelevie

beginner_source/nlp/sequence_models_tutorial.py

@@ -21,7 +21,7 @@
 part-of-speech tags, and a myriad of other things.
 
 
-LSTM's in Pytorch
+LSTMs in Pytorch
 ~~~~~~~~~~~~~~~~~
 
 Before getting to the example, note a few things. Pytorch's LSTM expects