Document the valid input range for `acos()` and `atan()`
Document the valid input range for `acos()` and `atan()`

(cherry picked from commit d359e159da9170417a65bbd4a5b7b4e64a01bded)

ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot