Examine source code of WebSocket Weasel

{
  "manifest_version": 2,
  "name": "WebSocket Weasel",
  "version": "2.1.1",
  "description": "A Handy Console to Communicate with WebSocket Servers",
  "homepage_url": "https://github.com/mhgolkar/Weasel",
  "icons": {
    "48": "icon-48.png",
    "120": "icon.svg",
    "128": "icon-128.png"
  },
  "browser_action": {
    "default_icon": "icon.svg",
    "default_title": "Weasel WebSocket Client"
  },
  "background": {
    "scripts": [
      "main.js"
    ]
  }
}