Allow customizing editor min height and width

[grahamhoyes]

Feature request

Use Case

I've started integrating this widget into an unfold-based admin site. For small (or empty) data, the min-height: 480px on .svelte-jsoneditor-wrapper leaves quite the large UI gap:

Current state

The .svelte-jsoneditor-wrapper class leaves a large UI gap, as well as inconsistent widths with other elements

Proposed Solution

There are a few ways around this I could see:

• Just remove min-height from .svelte-jsoneditor-wrapper, though there may be use cases where it's warranted. Still leaves the issue with the hard-coded width as well
• I could provide my own CSS / override the template to change the CSS class definition
• Making the class list customizable would be ideal. Default to .svelte-jsoneditor-wrapper for backwards compatibility, but would allow me to set eg w-full max-w-2xl from tailwind which gives a seamless UI as seen below

I'm happy to help make these changes!