README - Getting started

[patel-bhavin]

Adding a getting started section
Quick start commands
Adding explanation for our yaml files

[ljstella]

Couple of questions:

• Why are we putting them all in the readme.md as opposed to another file/folder and linking to it?
• Do we think folks are going to continue to scroll that far to see them?
• How will we ensure these stay up to date as the objects change?
• There are several other constraints on several of the fields in many files, that we've not indicated in these tables- are we planning to expand this more later, or just rely on validation failures to guide folks along?