Examine source code of Em-Dash Detector

{
  "manifest_version": 3,
  "name": "Em-Dash Detector",
  "version": "1.0",
  "description": "Detects em-dash characters on webpages and applies custom styling",
  "browser_specific_settings": {
    "gecko": {
      "id": "em-dash-detector@jcd.pub",
      "strict_min_version": "126.0"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "defaults.js",
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "defaults.js",
      "background.js"
    ]
  },
  "options_page": "options.html",
  "action": {
    "default_popup": "popup.html"
  }
}