Examine source code of X QRCode

{
  "name": "__MSG_appName__",
  "version": "0.3.0",
  "manifest_version": 2,
  "default_locale": "en",
  "description": "__MSG_appDesc__",
  "icons": {
    "16": "images/qrcode-16.png",
    "32": "images/qrcode-32.png",
    "48": "images/qrcode-48.png",
    "128": "images/qrcode-128.png"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": "images/qrcode-16.png",
    "default_title": "__MSG_appName__",
    "default_popup": "popup.html"
  },
  "homepage_url": "https://github.com/nuintun/x-qrcode",
  "permissions": [
    "activeTab",
    "contextMenus",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/content.js"
      ],
      "css": [
        "css/content.css"
      ],
      "run_at": "document_end"
    }
  ]
}