Examine source code of !Bang Quick Search

{
  "manifest_version": 2,
  "name": "!Bang Quick Search",
  "description": "DuckDuckGo !bang quick search",
  "version": "1.5.3",
  "author": "Brian Dawson",
  "permissions": [
    "*://*.google.com/*",
    "*://*.bing.com/*",
    "webRequest",
    "webRequestBlocking"
  ],
  "background": {
    "scripts": [
      "js/bang.js"
    ]
  },
  "icons": {
    "16": "images/bang.png",
    "48": "images/bang.png",
    "128": "images/bang.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e1ad9a1b-db30-4796-829c-99e6ccf518dc}"
    }
  }
}