Add an example using Xata

[fabien0102]

Add an example using Xata as database.

How to test

$ pnpm --filter example-with-xata run xata:init
$ pnpm --filter example-with-xata run dev

[boehs]

This is probably a better candidate for Xata's repository than ours

[fabien0102]

Yeah no problem, this was more for discovery, since you had an example with prisma, but no hard feeling 😉