Update GetInteriorHeading.md (citizenfx#936)

* Update GetInteriorHeading.md

Added information about return value

* Update GetInteriorHeading.md

Added alias, added inroduction version back and changed return value text

Author: freedy69

INTERIOR/GetInteriorHeading.md

@@ -1,18 +1,20 @@
 ---
 ns: INTERIOR
+aliases: ["_GET_INTERIOR_HEADING"]
 ---
-## _GET_INTERIOR_HEADING
+## GET_INTERIOR_HEADING
 
 ```c
 // 0xF49B58631D9E22D9
-float _GET_INTERIOR_HEADING(int interior);
+float GET_INTERIOR_HEADING(int interior);
 ```
 
 ```
-GET_INTERIOR_*
-
 NativeDB Introduced: v1493
 ```
 
 ## Parameters
-* **interior**:
+* **interior**: ID of the interior
+
+## Return value
+Returns interior heading in radians. Multiply the returned value with 57.29578 (or 180.0 / math.pi) to convert it to degrees.