Support for Svelte language

[jsonpoindexter]

Hi,

Love the IDE! I wanted to see if anyone else out there is interested in Svelte support? I will be happy to start working on a PR and will update this issue with the branch URL when I start working on it.

Svelte Info:
Extension: .svelte - Files contain a mix of JS/TS, HTML, CSS, and Svelte specific syntax

Homepage: https://svelte.dev/
Typescript Support: https://svelte.dev/blog/svelte-and-typescript (added mid 2020)

[jsonpoindexter]

I will be doing work on this branch: https://github.com/jsonpoindexter/Brackeys-IDE/tree/language/svelte