docs: incorrect difficulty modifiers

[ricmzn]

It looks like in the docs, the difficulty modifiers have modifier_reward and modifier_loss flipped around.

Docs: https://github.com/jtoppins/dct/blob/1606d02830fb83ef9f868fe76f920eeb99a32ff0/docs/designer.md#difficulty

Code:

dct/src/dct/systems/tickets.lua

Lines 22 to 45 in 1606d02

	local settings = {
	["easy"] = {
	["player_cost"] = 1.0,
	["modifier_loss"] = 0.5,
	["modifier_reward"] = 1.5,
	},
	["normal"] = {
	["player_cost"] = 1.0,
	["modifier_loss"] = 1.0,
	["modifier_reward"] = 1.0,
	},
	["hard"] = {
	["player_cost"] = 1.0,
	["modifier_loss"] = 1.5,
	["modifier_reward"] = 0.5,
	},
	["realistic"] = {
	["player_cost"] = 1.0,
	["modifier_loss"] = 1.0,
	["modifier_reward"] = 0,
	},
	["custom"] = {
	},
	}

This makes the docs give the impression that "easy" and "hard" are swapped, and that "realistic" would cause a coalition to never be able to lose, but the code is actually correct.