Examine source code of Tab Highlighter Helper

{
  "manifest_version": 2,
  "name": "Tab Highlighter Helper",
  "version": "1.0.0",
  "description": "Quickly toggle a subtle highlight around the current tab to help you focus on one page at a time.",
  "browser_specific_settings": {
    "gecko": {
      "id": "unique-random-addon@example.com",
      "strict_min_version": "91.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png"
    },
    "default_title": "Toggle a highlight on this tab",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}