Examine source code of Week number extension

{
  "name": "Week number extension",
  "version": "1.3.1",
  "description": "Do you find people who just have to use week numbers annoying? Week number extension is your tool for understanding their language.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "assets/icon.png",
    "default_title": "Week number extension"
  },
  "icons": {
    "16": "assets/icon.png",
    "32": "assets/icon.png",
    "48": "assets/icon.png",
    "96": "assets/icon.png"
  },
  "manifest_version": 2
}