Examine source code of Keyword Surfer Enhanced

{
  "manifest_version": 2,
  "name": "Keyword Surfer Enhanced",
  "version": "1.3",
  "description": "Displays search volumes, CPC, related keywords, highlights keywords, and allows export to CSV.",
  "permissions": [
    "activeTab",
    "storage",
    "downloads"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.google.com/search*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Keyword Surfer Enhanced"
  },
  "options_page": "options.html",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a15416cf-8062-4119-8bec-b0409f6658f2}"
    }
  }
}