Examine source code of Timeline Display

{
  "manifest_version": 2,
  "name": "timeline-menus",
  "version": "1.0",
  "description": "Add context menus to allow the storage and viewing of Wikipedia data",
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/wikipedia_globe_icon_16.png",
      "32": "icons/wikipedia_globe_icon_32.png"
    },
    "default_title": "Timeline"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/wikipedia_globe_icon_16.png",
    "32": "icons/wikipedia_globe_icon_32.png",
    "48": "icons/wikipedia_globe_icon_48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{de8d6a60-b042-4aa5-9f6b-e2916c707d70}"
    }
  }
}