Add DLRM model and Taobao Dataset support with "Implementing FedScale Deployment with Custom Dataset and Model" Run Guide

[RohanYim]

Why are these changes needed?

To help users understand how to add their own dataset and use custom models on FedScale. In addition, provide a basic practical example using the Taobao dataset and the DLRM model to help users better understand.

Related issue number

NA

Checks

• I've included any doc changes needed for https://fedscale.readthedocs.io/en/latest/
• I've made sure the following tests are passing.
• Testing Configurations
  • Dry Run (20 training rounds & 1 evaluation round)
  • Cifar 10 (20 training rounds & 1 evaluation round)
  • Femnist (20 training rounds & 1 evaluation round)