g.gui.iclass: add screenshot to manual page

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@55081 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/iclass/g.gui.iclass.html

@@ -33,6 +33,12 @@ as <em>g.gui.iclass</em>.
 
 </ul>
 
+<center>
+<br>
+<img src="iclass_frame.jpg" border="1" alt="Supervised Classification Tool">
+<br><br>
+</center>
+
 <p>
 <em>wxIClass</em> performs the first pass in the GRASS two-pass supervised image
 classification process; the GRASS module