Examine source code of Telegram Tab Auto-Close

{
  "manifest_version": 2,
  "name": "Telegram Tab Auto-Close",
  "version": "1.3",
  "author": "41eck",
  "icons": {
    "16": "icon.svg",
    "48": "icon_48.png",
    "128": "icon_128.png"
  },
  "description": "Closes tabs starting with https://t.me/ after 5 seconds.",
  "permissions": [
    "tabs",
    "https://t.me/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icon.svg",
    "default_title": "Telegram Tab Auto-Close"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{543f2c80-5e44-4f15-8886-b4e12bc37779}"
    }
  }
}