shell/ermine/fonts/manifest.json

{
  "families": [
    {
      "family": "Roboto Mono",
      "aliases": [
        "RobotoMono"
      ],
      "fallback_group": "monospace",
      "fallback": true,
      "fonts": [
        {
          "asset": "RobotoMono-Regular.ttf"
        },
        {
          "asset": "RobotoMono-Light.ttf",
          "weight": 300
        },
        {
          "asset": "RobotoMono-Medium.ttf",
          "weight": 500
        }
      ]
    }
  ]
}