Examine source code of Grailed Plus

{
  "manifest_version": 2,
  "name": "Grailed Plus",
  "version": "1.2.1",
  "description": "Enhancements for grailed.com listings.",
  "icons": {
    "48": "icons/grailed-48.png",
    "96": "icons/grailed-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.grailed.com/listings/*",
        "*://grailed.com/listings/*"
      ],
      "js": [
        "jquery-3.5.1.min.js",
        "priceHistory.js"
      ],
      "css": [
        "priceHistory.css"
      ]
    }
  ]
}