🚀 Feature: JSON output option

The user may want to parse the output manually in a different action step.

An option, for example, output_type: "json" could be useful to allow such customization more easily.

A format such as the following may be useful (all the params, plus the svg card url)

[
  {
      "id": "...",
      "title": "...",
      "timestamp": "...",
      "background_color": "...",
      "title_color": "...",
      "stats_color": "...",
      "width": "...",
      "duration": "...", // if applicable
      "image_url": "https://ytcards.demolab.com/?id=...&...",
  },
  {
      ...
  },
]

This can be coordinated with #24 since both involve adding output_type.