g.gui.vdigit manual: g.gui.rdigit link added

gui/wxpython/vdigit/g.gui.vdigit.html

@@ -293,6 +293,7 @@ boundaries are automatically attached to the chosen points.
 <a href="v.edit.html">v.edit</a>,
 <a href="v.category.html">v.category</a>,
 <a href="v.build.html">v.build</a>,
+<a href="g.gui.rdigit.html">g.gui.rdigit</a>,
 <a href="wxGUI.rdigit.html">wxGUI.rdigit</a>
 </em>