Examine source code of Simple Site Muter

{
  "manifest_version": 3,
  "name": "Simple Site Muter",
  "version": "1.3",
  "description": "Mute websites by top-level-domain with a simple tab right-click",
  "homepage_url": "https://github.com/alexkozler/simple-site-muter",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "tabs",
    "contextMenus",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "simple-site-muter@longrest",
      "strict_min_version": "112.0"
    }
  }
}