Update documentation

Docs/Luadoc/Lua.xml

@@ -1065,6 +1065,7 @@
 			<Function name='Move'/>
 			<Function name='SelectCourse'/>
 			<Function name='SelectSong'/>
+			<Function name='GetCurrentSections' />
 		</Class>
 		<Class name='NCSplineHandler'>
 			<Function name='get_spline'/>

Docs/Luadoc/LuaDocumentation.xml

@@ -3235,6 +3235,9 @@ save yourself some time, copy this for undocumented things:
 	<Function name='SelectCourse' return='bool' arguments='Course cCourse'>
 		Selects a course. Returns <code>false</code> on failure.
 	</Function>
+	<Function name='GetCurrentSections' return='{string}' arguments=''>
+		Returns the current sections in the MusicWheel, for use with a custom group select that supports sorting.
+	</Function>
 </Class>
 <Class name='NoteSkinManager'>
 	<Function name='GetMetric' return='string' arguments='string sElement, string sValue'>