Update documentation and clarify documentation

[wizage]

Is your feature request related to a problem? Please describe.
The docs are very lacking and we should update the documents to reflect the changes made amplify video.

Describe the solution you'd like
Move docs to wiki section or update the readme.

[wizage]

Docs we need:

• Getting started guide for livestream and VoD
• Commands descriptions (more in depth)
• Advance features
  • Cloudfront signed urls (a deep dive on the backend of how we do it)
  • amplify-video.js file (What does this have)
  • uploading assets
• Diagrams of what we build for you

[smp]

anything not specific to usage should go into wiki docs

• monitoring
• advanced features
• diagrams / arch
• customization path for Video resources

[smp]

@axptwig can you help with customization (based on your efforts) and command reference pages?

For amplify-video.js: https://github.com/awslabs/amplify-video/wiki/Application-Config
For Command Reference: https://github.com/awslabs/amplify-video/wiki/CLI-Reference
For Customization: https://github.com/awslabs/amplify-video/wiki/Customization
For VOD Quickstart..

1. Fresh implementation of UnicornFlix
2. Push to github and give sam access