Examine source code of Copy selected tabs

{
  "manifest_version": 2,
  "name": "Copy selected tabs",
  "description": "Add a menu option to copy selected tabs to the clipboard",
  "version": "0.1",
  "icons": {
    "24": "icons/copy_all.png"
  },
  "background": {
    "scripts": [
      "main.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab",
    "clipboardWrite",
    "menus",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0fb0042d-4504-487e-8b7e-f4150d70e55e}"
    }
  }
}