Examine source code of Hello world ggg

{
  "manifest_version": 2,
  "name": "Hello world ggg",
  "version": "4.5",
  "description": "Updated to 3.2",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_icon": "icon16.png",
    "default_popup": "popup.html"
  }
}