Examine source code of PDF Combiner

{
  "name": "PDF Combiner",
  "version": "1.1",
  "description": "PDF Combiner – Merge multiple PDF files into one document in seconds. Combine PDF files online and offline in one…",
  "manifest_version": 2,
  "default_locale": "en",
  "minimum_chrome_version": "100",
  "icons": {
    "16": "src/icons/16.png",
    "32": "src/icons/32.png",
    "48": "src/icons/48.png",
    "64": "src/icons/64.png",
    "96": "src/icons/96.png",
    "128": "src/icons/128.png"
  },
  "browser_action": {
    "default_title": "PDF Combiner",
    "default_icon": {
      "16": "src/icons/16.png",
      "24": "src/icons/24.png",
      "32": "src/icons/32.png"
    }
  },
  "options_page": "src/options/index.html",
  "background": {
    "scripts": [
      "service-worker-loader.js"
    ],
    "persistent": false
  },
  "web_accessible_resources": [
    "src/assets/*"
  ],
  "permissions": [
    "storage",
    "downloads",
    "contextMenus",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{909fc3a6-a88a-4f99-9c58-661317e3d226}"
    }
  }
}