Update +page.markdoc

Issue: 'npm create svelte' has been replaced with 'npx sv create'

Replaced old script with new, updated script. This will prevent users following your instructions from running into this error now and in the future.

src/routes/docs/quick-starts/sveltekit/+page.markdoc

@@ -35,7 +35,7 @@ You can skip optional steps.
 Create a SvelteKit project.
 
 ```sh
-npm create svelte@latest my-app && cd my-app && npm install
+npx sv create
 ```
 {% /section %}
 {% section #step-3 step=3 title="Install Appwrite" %}