Examine source code of Text Stats Viewer

{
  "manifest_version": 2,
  "name": "Text Stats Viewer",
  "version": "1.0",
  "description": "Analyzes text on the current webpage, counting words, characters, and sentences, with a chart and copyable results.",
  "permissions": [
    "activeTab",
    "storage",
    "clipboardWrite",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "ui/viewer.html",
    "default_title": "Text Stats Viewer"
  },
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "scripts/content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c6400a17-a635-418f-ad4e-4c955182c462}"
    }
  }
}