Create a system that will randomly engage a forage squad into a skirmish

[anthonyLuttrell]

Combat can be invoked when:

• A forage squad is sent out
  • Should be skirmish types
  • RNG to determine if they encounter something

About skirmishes

• Skirmishes appear randomly (let's try 75% of the time) to forage squads while out gathering resources or food
• Player can choose whether or not to engage in the skirmish
• Need a large pool of skirmish options (grasshoppers, wasp nest, small groups of ants)
• Each time a forage squad wins a skirmish, their odds for success increase slightly

Further details: https://github.com/warofants/wwa/wiki/Combat#skirmishes