Examine source code of AutoReload

{
  "manifest_version": 2,
  "name": "AutoReload",
  "version": "2.2.0",
  "description": "An extension that automatically reloads the specified tabs.",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "background": {
    "scripts": [
      "app.js"
    ],
    "type": "module",
    "persistent": true
  },
  "browser_action": {
    "default_icon": "icons/48.png",
    "default_title": "AutoReload",
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fd90566d-5620-4cb0-8ca6-725e17ec3691}",
      "strict_min_version": "58.0"
    }
  },
  "permissions": [
    "tabs",
    "idle",
    "storage"
  ]
}