Examine source code of Thin Scrollbar Everywhere

{
  "manifest_version": 2,
  "name": "Thin Scrollbar Everywhere",
  "version": "1.2",
  "description": "Thin Scrollbar Everywhere",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "bruh.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "sirvoraky@gmail.com"
    }
  }
}