Examine source code of dgg-gnomey-embed

{
  "manifest_version": 2,
  "name": "dgg-gnomey-embed",
  "version": "0.1",
  "description": "",
  "icons": {
    "48": "icons/gnomey-48-color.png",
    "96": "icons/gnomey-96-color.png"
  },
  "browser_action": {
    "default_icon": "icons/gnomey-96-color.png",
    "default_title": "DGG Gnomey Embed"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "scripting"
  ],
  "background": {
    "scripts": [
      "dgg.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d43b67bd-0ed7-41ab-92c9-80c64f926ea0}"
    }
  }
}