Examine source code of ChokoMines

{
  "manifest_version": 2,
  "name": "ChokoMines",
  "description": "Play the classic game in a chocolate flavour!",
  "version": "1.0",
  "author": "Rajasri",
  "browser_action": {
    "default_icon": "image/cubcakemines.png",
    "default_popup": "index.html"
  },
  "background": {
    "page": "index.html"
  },
  "icons": {
    "16": "image/image-logo-16x16.png",
    "32": "image/image-logo-32x32.png",
    "48": "image/image-logo-48x48.png",
    "128": "image/image-logo-128x128.png"
  }
}