Update README

Add documentation to the README, this should have all the basic information we have in our READMEs:

• Getting Started
  • Clone the project
  • NPM Install
  • npm script to start the application
• Developer section
  • explain the application architecture, how does NgRX work (components interact with facades that dispatch actions or access selectors, actions are reduced down into state, and projectors allow selectors to pull information out of state...)
  • how does data flow through the application
  • how does the PWA work
  • how is state maintained
• etc...