Examine source code of speedrun.com for firefox

{
  "name": "speedrun.com for firefox",
  "description": "Stay up to date on new world records and top times in your favorite categories.",
  "version": "2.0.2",
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "{510a7c75-12a9-4445-aecf-3fc1d89f9a4b}"
    }
  },
  "icons": {
    "16": "assets/icon16.png",
    "48": "assets/icon48.png",
    "128": "assets/icon128.png"
  },
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "index.html"
  }
}