Examine source code of Skip Intro Anime

{
  "manifest_version": 2,
  "name": "Skip Intro Anime",
  "version": "3.2",
  "description": "Botón para adelantar videos, configurable desde el popup.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ce03fee0-da74-42de-8ff0-28a3141cf0b6}"
    }
  }
}