Add disclaimer about unsafeRunSync in docs

[vpavkin]

Hello!
I know some beginner Scala devs who were confused when I told them they never should call unsafeRunSync in their code. They referenced http4s documentation, and indeed -- there's a ton of unsafeRunSync calls there.

I totally understand these are just small sandbox examples, but maybe for the sake of being beginner-friendly it's worth it to add a disclaimer on such pages?

thank you!

[bplommer]

I think even for REPL-based examples we should move towards assembling a complete program in the REPL then calling unsafeRunSync on it just once, rather than calling unsafeRunSync a bunch of times. Thoughts?

[armanbilge]

See also: https://mdoc-effect.indoorvivants.com/ce3/index.html

[vpavkin]

Nice, I really like the mdoc-effect approach

[rossabaker]

How much are we pitching the tutorials as "follow along in the REPL"? mdoc-effect breaks that model, but also avoids people copying-and-pasting bad habits. I wish there were some visual indication that magic is happening when an IO gets unwrapped.