Examine source code of Specto Ruler

{
  "manifest_version": 3,
  "name": "Specto Ruler",
  "description": "Your digital precision instrument for web design perfection. Measure pixels, align elements, and inspect layouts with crosshair accuracy. Perfect for designers and developers who demand pixel-perfect results.",
  "version": "2.0.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{17cbdf89-687d-420e-91ab-753ff5f72849}",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "64": "icons/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "Toggle Specto Ruler"
  },
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+Shift+M"
      }
    }
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ]
}