[DOC] Getting started with examples README

[dbericat]

Report incorrect documentation

Create README at examples and Jupyter notebook tutorials to describe what each example is meant to showcase. Similar to https://github.com/Project-MONAI/tutorials

I can see 3 categories:

1. MONAI Bundle -> MAP - link to key inference operator
2. Model trained with MONAI, but not bundle available -> MAP - link to key inference operator
3. Model NOT trained with MONAI -> MAP - link to how to create your own custom operator (I don't think we have this example yet)

Also add to documentation: https://docs.monai.io/projects/monai-deploy-app-sdk/en/latest/getting_started/examples.html#apps

[dbericat]

@AnilMistry @MMelQin @GreySeaWolf FYI