Examine source code of Another Tab Counter

{
  "name": "Tab Counter",
  "short_name": "Tab Counter",
  "author": "pureiboi",
  "developer": {
    "name": "pureiboi",
    "url": "https://github.com/pureiboi/tab-counter"
  },
  "version": "2.2.0",
  "description": "A button badge that shows the number of tabs open in a window",
  "homepage_url": "https://github.com/pureiboi/tab-counter",
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-counter@pureiboi.funapp.io",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "1": "icons/tabcounter-logo.plain.min.svg"
  },
  "permissions": [
    "storage",
    "tabGroups"
  ],
  "action": {
    "default_area": "tabstrip",
    "default_icon": "icons/tabcounter.plain.min.svg",
    "theme_icons": [
      {
        "dark": "icons/tabcounter-gray10.plain.min.svg",
        "light": "icons/tabcounter-gray90.plain.min.svg",
        "size": 1
      }
    ],
    "default_popup": "dist/popup.html",
    "default_title": "Tab Counter"
  },
  "options_ui": {
    "page": "dist/options.html"
  },
  "background": {
    "scripts": [
      "dist/common.js",
      "dist/background.js"
    ]
  }
}