Tweak to Opposed Checks

After a bit more testing, I realized the way active resistance worked in Tiny Colors was way too difficult. It left just a tiny window of success in most cases, so I don't know what I was thinking. I've changed that system to be a modifier to your goal number, which also changes the way NPCs are rated. They are now rated from 5 to -5, and this acts as their modifier to the PCs' checks.

As always, thank you and enjoy!