add predicate and reduce function doc

data/scripts/types/list.lua

@@ -68,16 +68,23 @@ function List:pop()
   return table.remove(self, #self)
 end
 
----Reduce.
----@param f function called with element, accumulator, index
----@param init any initial value of accumulator
+---Removes the first element in the list and returns it.
 ---@return any
+function List:pop_front()
+  return table.remove(self, 1)
+end
+
+---Reduce.
+---@generic T
+---@param f fun(element: any, accumulator: T, index: integer): T
+---@param init T|nil initial value of accumulator
+---@return T
 function List:reduce(f, init)
   return reduce(self, f, init)
 end
 
 ---Returns a new List of all elements of this list that match the predicate function.
----@param predicate function called with element
+---@param predicate fun(element: any): boolean
 ---@return List
 function List:filter(predicate)
   return filter(self, predicate)