Examine source code of Rickroll Blocker

{
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://*.youtube.com/*"
      ],
      "run_at": "document_start"
    }
  ],
  "name": "Rickroll Blocker",
  "version": "0.1.2",
  "description": "SAY GOODBYE!",
  "manifest_version": 2,
  "web_accessible_resources": [
    "warn/warn.html"
  ],
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{197caa3c-8cd5-4f85-b2d0-7b08504dcd39}"
    }
  }
}