Svelte Vite Starter

Known issue: onwarn code in svelte.config.js does not appear to work with Svelte v4.2.0.

Steps to reproduce:

1. Install Svelte for VS Code extension
2. There should be no warnings.
3. Update package.json: "svelte": "^4.2.0",
4. In terminal: npm install
5. In VS Code: Ctrl + Shift + P -> "Svelte: Restart Language Server"
6. ISSUE: You should see a11y warning.