Examine source code of Amazon-Sort

{
  "manifest_version": 3,
  "name": "Amazon-Sort",
  "author": "Bryon Smith",
  "version": "19",
  "description": "Group search results, filter and sort results by price or price per count.",
  "icons": {
    "48": "amazon-sort-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{43d52004-0e65-4d88-a520-4f5872caf110}"
    },
    "strict_min_version": "58.0"
  },
  "host_permissions": [
    "*://*.amazon.com/*",
    "*://*.amazon.com.au/*",
    "*://*.amazon.com.be/*",
    "*://*.amazon.com.br/*",
    "*://*.amazon.com.mx/*",
    "*://*.amazon.com.tr/*",
    "*://*.amazon.ae/*",
    "*://*.amazon.at/*",
    "*://*.amazon.ca/*",
    "*://*.amazon.ch/*",
    "*://*.amazon.cn/*",
    "*://*.amazon.co.jp/*",
    "*://*.amazon.co.nz/*",
    "*://*.amazon.co.uk/*",
    "*://*.amazon.co.za/*",
    "*://*.amazon.eg/*",
    "*://*.amazon.es/*",
    "*://*.amazon.fr/*",
    "*://*.amazon.de/*",
    "*://*.amazon.in/*",
    "*://*.amazon.ie/*",
    "*://*.amazon.it/*",
    "*://*.amazon.lu/*",
    "*://*.amazon.nl/*",
    "*://*.amazon.pl/*",
    "*://*.amazon.sa/*",
    "*://*.amazon.sg/*",
    "*://*.amazon.se/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.amazon.com/*",
        "*://*.amazon.com.au/*",
        "*://*.amazon.com.be/*",
        "*://*.amazon.com.br/*",
        "*://*.amazon.com.mx/*",
        "*://*.amazon.com.tr/*",
        "*://*.amazon.ae/*",
        "*://*.amazon.at/*",
        "*://*.amazon.ca/*",
        "*://*.amazon.ch/*",
        "*://*.amazon.cn/*",
        "*://*.amazon.co.jp/*",
        "*://*.amazon.co.nz/*",
        "*://*.amazon.co.uk/*",
        "*://*.amazon.co.za/*",
        "*://*.amazon.eg/*",
        "*://*.amazon.es/*",
        "*://*.amazon.fr/*",
        "*://*.amazon.de/*",
        "*://*.amazon.in/*",
        "*://*.amazon.ie/*",
        "*://*.amazon.it/*",
        "*://*.amazon.lu/*",
        "*://*.amazon.nl/*",
        "*://*.amazon.pl/*",
        "*://*.amazon.sa/*",
        "*://*.amazon.sg/*",
        "*://*.amazon.se/*"
      ],
      "js": [
        "amazon-sort.js"
      ]
    }
  ]
}