[EPIC] Make a MVP

[simlmx]

This big issues tracks what needs to be done to get Categorio ready for production. We are aiming for a future-proof MVP (i.e. that we'll be able to improve in a backward-compatible manner).

• Mock ups
• Github project setup
• Phases - the views with associated state and moves. Before we have timers we can add a temporary button to change the phase.
  • Loading
  • Write
  • Review
  • Leaderboard
• Timers between the phases when required