Examine source code of Triangle Calculator

{
  "manifest_version": 2,
  "name": "Triangle Calculator",
  "version": "1.0",
  "description": "Calculates the perimeter and area of a triangle",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Triangle Calculator",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a71d829f-970e-4621-8a87-5255cce810f1}"
    }
  }
}