Update document (training.md)

Summary:
Correct typo
standarized -> standardized
Regarding issue #3467

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Pull Request resolved: #3468

Reviewed By: zhanghang1989

Differential Revision: D31052099

Pulled By: ppwwyyxx

fbshipit-source-id: 4128566943cfa54fcebd357d6c1a1f9dda70a7da

Author: puhuk

docs/tutorials/training.md

@@ -14,7 +14,7 @@ Any customization on the training logic is then easily controlled by the user.
 
 ### Trainer Abstraction
 
-We also provide a standarized "trainer" abstraction with a
+We also provide a standardized "trainer" abstraction with a
 hook system that helps simplify the standard training behavior.
 It includes the following two instantiations: