Dynamically generate a heading for Extension Docs API pages

chrome/common/extensions/api/tabs.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": "tabs",
+    "description": "Use the <code>chrome.tabs</code> module to interact with the browser's tab system. You can use this module to create, modify, and rearrange tabs in the browser.",
     "types": [
       {
         "id": "Tab",
         "type": "object",
         "properties": {
           "id": {"type": "integer", "minimum": 0, "description": "The ID of the tab. Tab IDs are unique within a browser session."},
           "index": {"type": "integer", "minimum": 0, "description": "The zero-based index of the tab within its window."},
           "windowId": {"type": "integer", "minimum": 0, "description": "The ID of the window the tab is contained within."},
           "openerTabId": {"type": "integer", "minimum": 0, "optional": true, "description": "The ID of the tab that opened this tab, if any. This will only be present if the opener tab still exists."},
           "selected": {"type": "boolean", "description": "Whether the tab is selected.", "nodoc": true},
@@ skipping 910 matching lines @@
         "type": "function",
         "description": "Fired when a tab is replaced with another tab due to prerendering or instant.",
         "parameters": [
           {"type": "integer", "name": "addedTabId", "minimum": 0},
           {"type": "integer", "name": "removedTabId", "minimum": 0}
         ]
       }
     ]
   }
 ]