Create Getting Started documentation

[syvlabs]

Is your feature request related to a problem? Please describe.
The Getting Started doc will make it easier for new developers to come in, test out, and contribute to Feast.

This doc might include:

• Installation
• Usage
• Dev Environment Setup

[woop]

Will pick this up as soon as possible.

[woop]

I've started with this. There are a few things that need to be resolved first though.

• We need to add Redis to the Feast helm chart so that users don't need to set it up
• The Python SDK needs to be made available on Pypi (Push Feast Python SDK to https://pypi.org #121)

[woop]

I've started this Google Doc for us to contribute to a getting started guide. Would be great to get feedback or contributions from users. After we have settled the guide, we can convert it to markdown

Feast Getting Started Guide

[thirteen37]

I'm continuing work on this. Was previously blocked by a lack of a tagged release and corresponding artifacts to reference in the docs.

[woop]

Need to pick this up separately for the 0.3.0. Will create a new issue.