Examine source code of New Tab Suspender v2

{
  "description": "A very lightweight tab suspender to suspend inactive tabs that reduces an overall memory usage of firefox, uses a firefox native discard api",
  "manifest_version": 2,
  "name": "New Tab Suspender v2",
  "version": "2.0",
  "homepage_url": "https://github.com/ZhymabekRoman/TabSuspender",
  "author": "Zhymabek Roman (original by Pradeep Mishra)",
  "icons": {
    "48": "icons/border-48.png"
  },
  "background": {
    "scripts": [
      "bg.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage",
    "sessions"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0",
      "id": "{6a7a2d36-9dc4-4f78-89c6-c2be6554dbba}"
    }
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "New Tab Suspender",
    "default_popup": "popup.html"
  },
  "default_locale": "en"
}