add documentation for --rest-description in g.parser.html

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@52643 15284696-431f-4ddb-bdfa-cd5b030d7da7

general/g.parser/g.parser.html

@@ -158,6 +158,15 @@ generates a Web Processing Service process description. Example:
 v.in.db --wps-process-description
 </pre></div>
 
+<h2>reStructuredText (REST)</h2>
+
+The flag <b>--rest-description</b> added to a GRASS command
+generates a related help page template in reStructuredText. Example:
+
+<div class="code"><pre>
+v.in.db --rest-description
+</pre></div>
+
 
 <h2>TRANSLATION</h2>