Examine source code of Name Combiner Tool

{
  "manifest_version": 2,
  "name": "Name Combiner Tool",
  "version": "1.0",
  "description": "Quickly combine names directly in a popup or using a context menu.",
  "permissions": [
    "contextMenus",
    "clipboardWrite"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon-48.png",
      "128": "icon-128.png"
    }
  },
  "icons": {
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "namecombiner@example.com"
    }
  }
}