We need to clean up the structure of some of our javascript code:

• Consistently use require(), instead of a mix of require and include
• Move components into a separate file per component, as is the current best practise
• See if we should move to typescript (now might be a good time to do it, before we add more js)
• Set up eslint and a prettier config
• When moving to a separate file per component, switch from 4 spaces to 2, and remove .prettierrc