Examine source code of Device Zoom

{
  "manifest_version": 3,
  "name": "Device Zoom",
  "version": "1.0.3",
  "description": "Quick global zoom control with display-aware presets",
  "permissions": [
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": "icons/icon.svg",
    "default_title": "Device Zoom"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "device-zoom@tehmonk.com",
      "strict_min_version": "109.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "commands": {
    "cycle-zoom": {
      "suggested_key": {
        "default": "Alt+Z",
        "mac": "Alt+Z"
      },
      "description": "Cycle to next zoom level"
    }
  }
}