Examine source code of PDF Toolkit Pro

{
  "manifest_version": 2,
  "name": "PDF Toolkit Pro",
  "short_name": "PDF Toolkit",
  "version": "1.0.0",
  "description": "Complete PDF toolkit: convert, merge, edit, split, compress, annotate, sign, and more - all in your browser",
  "author": "José Neto",
  "browser_specific_settings": {
    "gecko": {
      "id": "pdf-toolkit-pro@josegpneto.dev",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_title": "PDF Toolkit Pro - 24 PDF Tools",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "offline_enabled": true
}