Remove note in lua-api.txt that there are no vector helper functions

PilzAdam · PilzAdam · commit c813a3cc53f0 · 2013-07-08T13:41:46.000+02:00
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
@@ -507,8 +507,7 @@ Representations of simple things
 --------------------------------
 Position/vector:
   {x=num, y=num, z=num}
-Currently the API does not provide any helper functions for addition,
-subtraction and whatever; you can define those that you need yourself.
+For helper functions see "Vector helpers".
 
 pointed_thing:
   {type="nothing"}
