Examine source code of Simple Calculator

{
  "manifest_version": 2,
  "name": "Simple Calculator",
  "version": "1.0.0",
  "description": "A simple calculator extension with basic arithmetic operations",
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Calculator"
  },
  "icons": {
    "48": "assets/icons/icon-48.png",
    "96": "assets/icons/icon-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{539035a7-0f10-43c1-af6b-62e3cbe463ea}"
    }
  }
}