Consider updating output directory

[benmccann]

We've started recommending folks put their adapter output under .svelte-kit/begin for example. It's not required, but if it works on the platform it might be nice pattern to follow. And in that case also write the entry.js file to .svelte-kit/begin/intermediate to separate it from the output. I have a PR out to update Netlify as an example (sveltejs/kit#2058) and update the documentation (sveltejs/kit#2055)

Thanks for creating this adapter!

How's it going on moving this to a new official home?

[ryanbethel]

It should work fine putting all but the app.arc file in .svelte-kit. I will make that change. I am just returning from vacation so I should be able to get a first release out this week. The repo` will be moving to the architect org.