Add example about how to use GPU

[mosoriob]

🚀 Feature Request

The app specification should have the following containerArgs

      "containerArgs": [
        {
          "name": "NVIDIA Flag",
          "description": "Flag to enable NVIDIA cuda",
          "inputMode": "FIXED",
          "arg": "--nv",
          "notes": {
            "isHidden": true
          }
        }
      ],

🔈 Motivation

🛰 Alternatives

📎 Additional context