Examine source code of Intimidating Horse

{
  "manifest_version": 2,
  "name": "Horse Reminder",
  "version": "1.0",
  "description": "Shows a horse after 2 minutes on Twitter to stop doomscrolling.",
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      },
      "id": "{e178aa42-7f51-4cdd-a059-75cbd9fa5f8e}"
    }
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.twitter.com/*",
        "*://*.x.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "horse.png",
    "ominous_music.mp3",
    "horse_neigh.wav"
  ]
}