[DataPipe] Adding usage examples for IterDataPipes (#73033)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/73033
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D34313793
Pulled By: NivekT
fbshipit-source-id: 51125be2f79d73d02658b2b1c2691f96be8d4769
(cherry picked from commit 3e3c2df7c6a9f6cb51f2343254063487a091729a)
