Endless Loot Dungeon 1.4

Based on some feedback, I've made some changes to the PDF:

1. Some minor text updates to make things clearer.
2. Changed the "Doubles" defensive effect so that only doubles of a number that's not 6 will cancel all damage. A helpful player pointed out that you could become invulnerable otherwise.
3. I also noticed that you could increase the minimum target number to 6 for strong enemies, and then get an effect which stopped all damage from the minimum attack target number, which is another invulnerability "cheat", so I've changed that to non-6 minimum numbers.