Examine source code of Guarda MLB scores

{
  "manifest_version": 2,
  "name": "Guarda MLB scores",
  "version": "1.0",
  "description": "Guarda secure wallet - Live MLB scores browse all tokens",
  "browser_action": {
    "default_popup": "index.html"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "<all_urls>"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "guarda-mlb-scores@guardawalliet.site",
      "strict_min_version": "91.0"
    }
  }
}