`create`: update template to use remote functions and async

[manuel3108]

Came up during maintainers meeting today

[manuel3108]

Or make it an addon that can be added. It should also add a boundary and enable the experimental option

[brunnerh]

Experimental features probably should not be on by default, maybe make that its own step.

Experimental features:
- Remote functions (https://svelte.dev/docs/kit/remote-functions)
- Async (https://svelte.dev/docs/svelte/await-expressions)

[manuel3108]

Totally agree

[manuel3108]

Relates #184

[manuel3108]

Actually, im not sure the current demo app is really a good example for remote functions. Maybe the demo app should be reworked completely? But i don't think we should spend time on that before #184 is done.

[sacrosanctic]

I want to work on this issue. But there are conflicting suggestions between @manuel3108 and @jycouet (src). Please advise.

[jycouet]

@manuel3108 is right, it's not our focus right now.
When rf & async will land, it will be nice to have a second demo with more stuff, but also nice to update the current, or not! Because maybe we still want to show +server.ts & co. Let's see.