documentation: Standardize examples

Most examples in the XML documentation use the
example tag to demonstrate examples, which gets
parsed specially in the Wiki to make it easier
to follow for users.

This fixes a few modules to use the example
tag instead of vanilla para tags to bring them
in line with the standard syntax.

ASTERISK-29777 #close

Change-Id: I9acb6cc5faf1d220e73c6dd28592371d768d279b

funcs/func_devstate.c

@@ -90,8 +90,10 @@
 		</syntax>
 		<description>
 			<para>The HINT function can be used to retrieve the list of devices that are
-			mapped to a dialplan hint. For example:</para>
-			<para>NoOp(Hint for Extension 1234 is ${HINT(1234)})</para>
+			mapped to a dialplan hint.</para>
+			<example title="Hint for extension 1234">
+			same => n,NoOp(Hint for Extension 1234 is ${HINT(1234)})
+			</example>
 		</description>
 	</function>
  ***/