Examine source code of Page Info Helper

{
  "manifest_version": 2,
  "name": "Page Info Helper",
  "version": "1.0.0",
  "description": "Quickly scan the current page for word and link counts, and optionally highlight all links. Built for Firefox and AMO‑friendly (no inline scripts, minimal permissions).",
  "browser_specific_settings": {
    "gecko": {
      "id": "page-info-helper@example.com"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Page Info Helper",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  }
}