Examine source code of cazadescuentos

{
  "manifest_version": 2,
  "name": "cazadescuentos",
  "version": "1.28",
  "default_locale": "en",
  "description": "Allows you to follow the items you are interested to buy if they were cheaper, notifying you once their price decreases",
  "icons": {
    "48": "icons/48/app.png",
    "96": "icons/96/app.png"
  },
  "web_accessible_resources": [
    "icons/*"
  ],
  "permissions": [
    "storage",
    "notifications",
    "alarms"
  ],
  "background": {
    "scripts": [
      "scripts/common.js",
      "main-bundle.js",
      "scripts/background-script.js"
    ]
  },
  "browser_action": {
    "default_title": "cazadescuentos",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/48/app.png",
      "96": "icons/96/app.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.liverpool.com.mx/*",
        "https://www.zara.com/*",
        "https://www2.hm.com/*",
        "https://m2.hm.com/*",
        "https://www.coppel.com/*",
        "https://www.mercadolibre.com.mx/*",
        "https://articulo.mercadolibre.com.mx/*",
        "https://www.costco.com.mx/*",
        "https://www.costco.com/*",
        "https://www.homedepot.com/*",
        "https://www.homedepot.com.mx/*",
        "http://www.homedepot.com.mx/*",
        "https://www.ebay.com/itm/*",
        "https://www.officedepot.com.mx/*",
        "https://www.officedepot.com/*",
        "https://www.sanborns.com.mx/*",
        "https://www.sams.com.mx/*",
        "https://www.samsclub.com/*",
        "https://shop.nordstrom.com/s/*",
        "https://www.elektra.com.mx/*",
        "https://www.costco.com.mx/*",
        "https://www.costco.com/*",
        "https://www.walmart.com.mx/*",
        "https://super.walmart.com.mx/*",
        "https://www.bestbuy.com.mx/*",
        "https://www.bestbuy.com/*",
        "https://www.elpalaciodehierro.com/*",
        "https://www.amazon.com.mx/*"
      ],
      "js": [
        "scripts/common.js",
        "main-bundle.js",
        "external-scripts/sidenavCzd.js",
        "scripts/active-tab-script.js"
      ]
    }
  ]
}