[feature] Support importing colour styles as a colour palette

[tinacious]

Support importing JSON from this tool: https://colour-tools.pages.dev/palettes

{
  "name": "Tinacious Design",
  "colours": [
    { "name": "pink", "colour": "#ff3399" },
    { "name": "blue", "colour": "#33d5ff" },
    { "name": "grey", "colour": "#b3b3d4" },
    { "name": "green", "colour": "#00d364" },
    { "name": "purple", "colour": "#cc66ff" },
    { "name": "yellow", "colour": "#ffcc66" },
    { "name": "blue", "colour": "#00ced1" },
    { "name": "midnight-sky", "colour": "#1d1d26" },
    { "name": "overcast-sky", "colour": "#c8c8d5" },
    { "name": "tangerine", "colour": "#ffaa00" },
    { "name": "red", "colour": "#f10f69" }
  ]
}