Fire Aspect and Flame should be added to the Nether Fortress' loot table

Currently the loot from the Nether Fortress isn't great. The loot is underwhelming and lacks uniqueness. The addition of the Rib armor trim has made this a little better, but I think the loot could be further improved. With that said, I think adding Fire Aspect and Flame enchantment books to the Nether Fortress loot table would be good. It makes sense since both of those enchantments are fire related and the Nether is a hellish dimension. Adding those 2 books also makes them easier to obtain if the player specifically wants those enchantments. This helps give the Nether Fortress more unique loot and another purpose for going there outside of the main 2 purposes currently - blade rods, and the Rib armor trim.