Examine source code of Budget control for Amazon

{
  "name": "Budget control for Amazon",
  "version": "1.1.0",
  "description": "The plugin allows to control you spendings on Amazon",
  "permissions": [
    "storage",
    "tabs",
    "activeTab",
    "https://amazon.com/",
    "https://www.amazon.com/",
    "https://amazon.com.au/",
    "https://www.amazon.com.au/",
    "https://amazon.com.br/",
    "https://www.amazon.com.br/",
    "https://amazon.ca/",
    "https://www.amazon.ca/",
    "https://amazon.cn/",
    "https://www.amazon.cn/",
    "https://amazon.fr/",
    "https://www.amazon.fr/",
    "https://amazon.de/",
    "https://www.amazon.de/",
    "https://amazon.in/",
    "https://www.amazon.in/",
    "https://amazon.it/",
    "https://www.amazon.it/",
    "https://amazon.co.jp/",
    "https://www.amazon.co.jp/",
    "https://amazon.com.mx/",
    "https://www.amazon.com.mx/",
    "https://amazon.es/",
    "https://www.amazon.es/",
    "https://amazon.com.tr/",
    "https://www.amazon.com.tr/",
    "https://amazon.co.uk/",
    "https://www.amazon.co.uk/"
  ],
  "background": {
    "scripts": [
      "background.bundle.js"
    ]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "run_at": "document_idle",
      "js": [
        "jquery-3.4.1.min.js",
        "contentscript.bundle.js"
      ],
      "matches": [
        "https://amazon.com/*",
        "https://www.amazon.com/*",
        "https://amazon.com.au/*",
        "https://www.amazon.com.au/*",
        "https://amazon.com.br/*",
        "https://www.amazon.com.br/*",
        "https://amazon.ca/*",
        "https://www.amazon.ca/*",
        "https://amazon.cn/*",
        "https://www.amazon.cn/*",
        "https://amazon.fr/*",
        "https://www.amazon.fr/*",
        "https://amazon.de/*",
        "https://www.amazon.de/*",
        "https://amazon.in/*",
        "https://www.amazon.in/*",
        "https://amazon.it/*",
        "https://www.amazon.it/*",
        "https://amazon.co.jp/*",
        "https://www.amazon.co.jp/*",
        "https://amazon.com.mx/*",
        "https://www.amazon.com.mx/*",
        "https://amazon.es/*",
        "https://www.amazon.es/*",
        "https://amazon.com.tr/*",
        "https://www.amazon.com.tr/*",
        "https://amazon.co.uk/*",
        "https://www.amazon.co.uk/*"
      ]
    }
  ],
  "web_accessible_resources": [
    "semantic.min.css",
    "icon.min.css",
    "themes/default/assets/fonts/*"
  ],
  "browser_action": {},
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "manifest_version": 2
}