i18n options missing

Currently the [svelte-jsoneditor](https://github.com/josdejong/svelte-jsoneditor) is missing options for internationalization.

I am thinking of two ways, how this can be archived:

* The package ships translations and the developer can set them via a translation prop, eg `translation: 'de-De'`
* The package don't ship translations, but text can be overwritten eg: ```{ texts: {searchFindText: 'Finden'}}```

The issue does not identify files, tests, or an entry point. First clarify whether shipped translations or caller-provided text overrides are required, then define the supported option shape and how completion will be verified.

Written by the indexing model from the issue text.