Enemy AI: NavMesh prototype

First demo of an enemy pathfinding prototype for ARHS using NavMeshes. It's pretty basic for now; all this currently shows off is the pathfinding qualities of NavMeshes. There is still much to do before this AI is ready to be implemented into the game.

Planned next steps:

• Refine corner navigation (the prototype enemy currently gets stuck on corners for a non-negligible amount of time)
• Prevent enemies from pushing players out of bounds when attacking
• Make the enemy have to see the player in order to be able to navigate to them
  • Make the enemy lose awareness of the player after a certain amount of time without the player in its line of sight