[FEATURE_REQUEST] Add vision transformers model to image classification

[kbjiang]

Description

The transformer-based image classification model is becoming popular. It will be nice to include it in this repo.

Expected behavior with the suggested feature

• similar classification performance as the CNN based models

Other Comments

[ShreyasJoshi7]

@kbjiang I have created a PR which demonstrates the inference of transformer-based image classification using DeiT. I would appreciate if you could have a look at it. Let me know if you need more things to be added to it. This is the link to the PR
Cheers!