Reorganize the repo

[hawkrives]

• Moves the app demos to /demo
• Removes the cordova project, since it's tricky to build and includes a duplicate of the entire project
• Includes a minified GIF of the app demo into the README
• Removes requireJS and replaces it with ES Modules (import/export)
• Converts a couple of classes to es6 class
• Adds prettier and npm start commands and reformats the code

Edit: A live demo is at https://mwgevolution-wxokhlcszh.now.sh/demo/