Examine source code of Instant Meta Checker

{
  "manifest_version": 3,
  "name": "Instant Meta Checker",
  "description": "Instantly check meta tags, headings, and SEO data for any webpage.",
  "version": "1.0",
  "permissions": [
    "scripting",
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon128.png"
  },
  "icons": {
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "instant-meta-checker@example.com",
      "strict_min_version": "109.0"
    }
  }
}