Fix ambiguity in angle_difference function documentation

Co-authored-by: A Thousand Ships <[email protected]>

doc/classes/@GlobalScope.xml

@@ -90,7 +90,7 @@
 			<param index="0" name="from" type="float" />
 			<param index="1" name="to" type="float" />
 			<description>
-				Returns the difference between the two angles, in the range of [code][-PI, +PI][/code]. When [param from] and [param to] are opposite, returns [code]-PI[/code] if [param from] is smaller than [param to], or [code]PI[/code] otherwise.
+				Returns the difference between the two angles (in radians), in the range of [code][-PI, +PI][/code]. When [param from] and [param to] are opposite, returns [code]-PI[/code] if [param from] is smaller than [param to], or [code]PI[/code] otherwise.
 			</description>
 		</method>
 		<method name="asin">