Examine source code of tabsleeper

{
  "name": "tabsleeper",
  "version": "0.4.0",
  "description": "Lightweight tab management",
  "manifest_version": 3,
  "permissions": [
    "tabs"
  ],
  "icons": {
    "128": "icon/128.png"
  },
  "background": {
    "scripts": [
      "build/dist/background.js"
    ]
  },
  "content_security_policy": {
    "extension_pages": "default-src 'self'"
  },
  "action": {
    "default_icon": {
      "19": "icon/browserAction/19.png",
      "38": "icon/browserAction/38.png"
    },
    "default_title": "Sleep this window",
    "default_popup": "static/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gecko-extension@tabsleeper.com",
      "strict_min_version": "105.0"
    }
  }
}