REPL integration

[Rich-Harris]

Watching Ron Au's (amazing) Svelte Summit talk reminded me that we need to integrate the REPL with Svelte Kit, since it's currently based on the hopefully-soon-to-be-deprecated sveltejs/template

[jacob-8]

Would you be able to switch to the Monaco editor in the process as used by Typescript's REPL and Tailwind Play? It kills me that I can't use the VSCode line duplicating/reordering/deleting/commenting shortcuts or code formatting as is possible in those other REPL's. Svelte's REPL has contributed greatly to Svelte's ease of learning, and this would take it to the next level.

https://github.com/microsoft/TypeScript-Website/blob/v2/packages/playground/package.json#L22
https://github.com/tailwindlabs/play.tailwindcss.com/blob/master/package.json#L40

I realize this may be a separate issue and also want to mention that I would be willing to take a stab it if that would be helpful when the time for the REPL transition comes up.

[Rich-Harris]

Going to close this as discussion around the next version of the REPL is happening elsewhere (albeit slowly, and not in public yet). In all likelihood we'll be using CodeMirror 6 rather than Monaco, but we're definitely aware of those features and it would be great to include them.