Examine source code of Open URLs in Container

{
  "manifest_version": 2,
  "name": "Open URLs in Container",
  "version": "0.0.2",
  "description": "Open any URL (not just those with a specific domain) in a multi-account container",
  "developer": {
    "name": "Battlemoose",
    "url": "mailto:hughblackall@gmail.com"
  },
  "default_locale": "en",
  "permissions": [
    "tabs",
    "contextualIdentities",
    "cookies",
    "storage"
  ],
  "background": {
    "scripts": [
      "background/tab-updated-listener.js"
    ]
  },
  "options_ui": {
    "page": "settings/settings.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{81448a9e-a376-409b-a744-4234b6770e7f}"
    }
  }
}