Update doc with -doctool.

doc/base/classes.xml

@@ -4371,7 +4371,7 @@
 			Stop a given voice.
 			</description>
 		</method>
-		<method name="free">
+		<method name="free_rid">
 			<argument index="0" name="rid" type="RID">
 			</argument>
 			<description>