Examine source code of HJKLGg Navigation

{
  "manifest_version": 2,
  "name": "HJKL Navigation",
  "version": "1.0",
  "description": "Use hjkl keys to navigate webpages like in Vim.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3dd767e8-16be-4f2b-8f18-0c747cf9f2eb}"
    }
  }
}