Examine source code of Search Enhancement

{
  "manifest_version": 2,
  "name": "Search Enhancement",
  "version": "2.0",
  "description": "Adds links to Reddit, Wikipedia, Twitter directlly on Google search page",
  "icons": {
    "48": "icons/search-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "include_globs": [
        "*://*.google.*/*"
      ],
      "js": [
        "search.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{621ab849-298f-468a-b4b0-7fea6618717e}"
    }
  }
}