Snowpack: Update app-template-svelte-typescript to work with Svelte’s TS support

[drwpow]

Svelte finally announced TypeScript support, which means the TypeScript Svelte template is (slightly) out-of-date: it uses a custom TS setup, and it should probably be updated to closely match the new setup recommended by the Svelte team.

Tasks would include:

• updating <script> to <script lang="ts">
• adding "extends": "@tsconfig/svelte/tsconfig.json" to tsconfig.json (and possibly deleting most if not all of the rest of the config)
• updating the svelte and svelte-check dependency versions in both app-template-svelte and app-template-svelte-typescript
• ??? (any other suggestions in that blog post 👆 would be welcome)

This would be a great first issue for someone!

[drwpow]

cc @davidleger95 no pressure at all but this is a good intro to the repo!

[davidleger95]

Awesome! I’ll take a look at it tomorrow 🙂

[drwpow]

Resolved as part of #660