Rule updates

I made some modifications to the Starship Battles add-on rules. I’mmin the midst of editing an article for Harbinger that will feature them and I found some typos, added some measurement suggestions and also changed the optional combat rules so that it is only one ship at a time to avoid having a player pick their two largest ships to attempt to decimate their opponent.

Update: There is now a new optional rule to add the Class difference as a positive or negative modifier to ranged fire but not PD attacks.