Added sizing.

Globally, for all apps:

{
  // Horizontal screen coverage, as a percentage (defaults to 95).
  "HorizontalScreenCoverage": 95,

  // Vertical screen coverage, as a percentage (defaults to 95).
  "VerticalScreenCoverage": 95,

  // How much room to leave between the top of the terminal and the top of the screen, in pixels.
  "VerticalOffset": 0
}

Or per app:

{
  "Apps": [
    {
      "Name": "Terminal",

      // Horizontal screen coverage, as a percentage (defaults to 95).
      "HorizontalScreenCoverage": 95,

      // Vertical screen coverage as a percentage (defaults to 95).
      "VerticalScreenCoverage": 95,
    
      // How much room to leave between the top of the terminal and the top of the screen, in pixels.
      "VerticalOffset": 0
    },
    ...
  ]
}