Deprecated mmar (Project-MONAI#1477)

Deprecated mmar, now consider the latest model zoo bundles
https://github.com/Project-MONAI/model-zoo/tree/dev/models, main use
cases: https://github.com/Project-MONAI/tutorials/tree/main/model_zoo.

### Checks
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- [ ] Avoid including large-size files in the PR.
- [ ] Clean up long text outputs from code cells in the notebook.
- [ ] For security purposes, please check the contents and remove any
sensitive info such as user names and private key.
- [ ] Ensure (1) hyperlinks and markdown anchors are working (2) use
relative paths for tutorial repo files (3) put figure and graphs in the
`./figure` folder
- [ ] Notebook runs automatically `./runner.sh -t <path to .ipynb file>`

Signed-off-by: KumoLiu <[email protected]>

Author: KumoLiu

README.md

@@ -283,8 +283,6 @@ This notebook demonstrates how the three libraries from the official PyTorch Eco
 This tutorial uses the MedNIST scan (or alternatively the MNIST) dataset to demonstrate MONAI's variational autoencoder class.
 ##### [interpretability](./modules/interpretability)
 Tutorials in this folder demonstrate model visualisation and interpretability features of MONAI. Currently, it consists of class activation mapping and occlusion sensitivity for 3D classification model visualisations and analysis.
-##### [Transfer learning with MMAR](./modules/transfer_mmar.ipynb)
-This tutorial demonstrates a transfer learning pipeline from a pretrained model in [Clara Train's Medical Model Archive format](https://docs.nvidia.com/clara/clara-train-sdk/pt/mmar.html).  The notebook also shows the use of LMDB-based dataset.
 
 ##### [Transform visualization](./modules/transform_visualization.ipynb)
 This tutorial shows several visualization approaches for 3D image during transform augmentation.