Examine source code of Cache Nut

{
  "manifest_version": 3,
  "name": "Cache Nut",
  "author": "Huy Duong",
  "icons": {
    "16": "assets/icons/cachenut-acorn-16.png",
    "32": "assets/icons/cachenut-acorn-32.png",
    "48": "assets/icons/cachenut-acorn-48.png",
    "96": "assets/icons/cachenut-acorn-96.png",
    "128": "assets/icons/cachenut-acorn-128.png"
  },
  "description": "A shared clipboard across browsers that is encrypted and anonymous.",
  "homepage_url": "https://cachenut.com",
  "short_name": "Cache Nut",
  "permissions": [
    "activeTab",
    "bookmarks",
    "clipboardRead",
    "clipboardWrite",
    "contextMenus",
    "storage",
    "tabs"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@cachenut.com",
      "strict_min_version": "123.0"
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/cachenut-acorn-16.png",
      "32": "assets/icons/cachenut-acorn-32.png",
      "48": "assets/icons/cachenut-acorn-48.png",
      "96": "assets/icons/cachenut-acorn-96.png",
      "128": "assets/icons/cachenut-acorn-128.png"
    },
    "default_title": "Cache Nut"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "background": {
    "scripts": [
      "js/background.bundle.js"
    ]
  },
  "version": "1.0.3"
}