doc[README][RTD]: Refactor README from RST to MarkDown and add jupyter usage installation instructions.

Description

• Added jupyter notebook installation instructions (i.e. pip install notebook==5.6.1)
• Moved README from RST to MarkDown for sanity.
• Updated RTD instructions as well for the jupyter part.
• Removed redundant instructions and collected the steps and bash code together.

How Has This Been Tested?

Relevant Documents (optional)

Types of changes

• Docs (changes to the documentation)
• Refactor (refactoring code with no functionality changes)
• Style (formatting changes only, no code changes)

Checklist:

Reviewers

@roscar @kluyvert @rovensky