Fix discrepancy between docs and actual functions

init.lua

@@ -59,7 +59,7 @@ local function monoid(def)
 	return mon
 end
 
-player_monoids.monoid = monoid
+player_monoids.make_monoid = monoid
 
 function mon_meta:add_change(player, value)
 	local p_name = player:get_player_name()

standard_monoids.lua

@@ -34,7 +34,7 @@ local function v_mult_fold(identity)
 	end
 end
 
-local monoid = player_monoids.monoid
+local monoid = player_monoids.make_monoid
 
 -- Speed monoid. Effect values are speed multipliers. Must be nonnegative
 -- numbers.