Adds referee screen and deities.

Updates bestiary with links to nonhuman racial modifiers.

src/pages/bestiary/fighter.md

@@ -26,6 +26,7 @@ An adventurer that specializes in combat.
 
 -   **Leader**: 50% chance groups of 4+ are led by a higher level fighter (1d4 HD higher).
 -   **Weapon Versatility**: May be found wielding various types of [weapons](https://www.planarvagabond.com/rules/combat.html#weapons).
+-   [**Non-human Modifiers**](./nonhuman-modifiers.html): Non-human fighters may have additional abilities or modified statistics.
 
 ### At Higher Levels