Dynamically generate a heading for Extension Docs API pages

chrome/common/extensions/api/bookmarks.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "bookmarks",
+    "description": "Use the <code>chrome.bookmarks</code> module to create, organize, and otherwise manipulate bookmarks.",
     "uses_feature_system": true,
     "channel": "stable",
     "dependencies": ["permission:bookmarks"],
     "contexts": ["blessed_extension"],
     "properties": {
       "MAX_WRITE_OPERATIONS_PER_HOUR": {
         "value": 100,
         "description": "The maximum number of <code>move</code>, <code>update</code>, <code>create</code>, or <code>remove</code> operations that can be performed each hour. Updates that would cause this limit to be exceeded fail."
       },
       "MAX_SUSTAINED_WRITE_OPERATIONS_PER_MINUTE": {
@@ skipping 489 matching lines @@
       },
       {
         "name": "onImportEnded",
         "type": "function",
         "description": "Fired when a bookmark import session is ended.",
         "parameters": []
       }
     ]
   }
 ]