Examine source code of YouTube Grid Customizer

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "2.2.0",
  "description": "__MSG_extensionDescription__",
  "homepage_url": "https://github.com/RyanKelleyCosing/youtube-grid-customizer",
  "default_locale": "en",
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "__MSG_extensionName__",
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    }
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "*://www.youtube.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d4cbb48e-8e10-443d-b9a6-e4cefce04476}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ]
}