- NPCs
    - NPCs now use the Dijkstra's algorithm for pathfinding
    - NPCs now use the raycaster and Vision components to find the
    player
    - Less magic numbers in NPC AI code
- Inventory system
    - Inventory selection now wraps around
    - Added a small arrow to indicate selection in addition to text
    color (might help colour blind people?)
- Helpers
    - Wrote some small helper functions to deal with directions and
    coordinates