Examine source code of Scrolled

{
  "description": "Displays the current scroll percentage of the active page.",
  "manifest_version": 3,
  "name": "Scrolled",
  "version": "1.5",
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "content_scripts/*",
        "popup/style.css"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "scrolled-addon@eucaue"
    }
  },
  "action": {
    "default_icon": "icons/icon-128-light.png",
    "theme_icons": [
      {
        "dark": "./icons/icon-16-light.png",
        "light": "./icons/icon-16-dark.png",
        "size": 16
      },
      {
        "dark": "./icons/icon-32-light.png",
        "light": "./icons/icon-32-dark.png",
        "size": 32
      },
      {
        "dark": "./icons/icon-128-light.png",
        "light": "./icons/icon-128-dark.png",
        "size": 128
      }
    ],
    "default_title": "Scrolled",
    "default_popup": "popup/index.html"
  },
  "background": {
    "scripts": [
      "background_scripts/background.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/scrollListener.js"
      ]
    }
  ]
}