Add method description to conduit.query

Summary: As suggested in T6950, add the method description to the response from `conduit.query`.

Test Plan: Called `echo '{}' | arc call-conduit conduit.query` and verified that the response contained the method description.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11467

src/applications/conduit/method/ConduitQueryConduitAPIMethod.php

@@ -31,6 +31,7 @@ final class ConduitQueryConduitAPIMethod extends ConduitAPIMethod {
     $names_to_params = array();
     foreach ($classes as $class) {
       $names_to_params[$class->getAPIMethodName()] = array(
+        'description' => $class->getMethodDescription(),
         'params' => $class->defineParamTypes(),
         'return' => $class->defineReturnType(),
       );