Examine source code of ClubLink

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon-128.png",
    "default_title": "ClubLink"
  },
  "name": "ClubLink",
  "description": "ClubLink.to browser extension",
  "homepage_url": "https://ClubLink.to",
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "activeTab",
    "https://joinclubhouse.com/*",
    "https://ios.joinclubhouse.com/*",
    "https://www.joinclubhouse.com/*"
  ],
  "version": "0.1",
  "manifest_version": 2
}