Update the README.md

[rangareddy]

The following things needs to be updated in README.md file

1. In the Table of Contents section, the link for the 2nd point (2. Feature Highlights) is not working.
2. Product Walkthrough should be added to the Table of Contents section, with remaining items such as Explore your Tables, Table Stats, etc. nested under it.
3. The content for Step 1 and Step 3 should be merged under the Install the Metadata Extractor Tool section.
4. There is an inconsistency in the number of deployment methods mentioned for the Metadata Extractor Tool: 3 methods are listed in one section, while 4 methods (jar, docker, helm, and AWS Glue) are mentioned in another section.