Examine source code of Ratnot

{
  "manifest_version": 2,
  "name": "Ratnot",
  "description": "A live bidding companion for Whatnot Auctions & Surprise Sets.",
  "version": "0.8.18",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage"
  ],
  "web_accessible_resources": [
    "injected.js",
    "fonts/*",
    "content-scripts/content.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ratnot@dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.whatnot.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ],
      "world": "ISOLATED"
    }
  ],
  "browser_action": {}
}