[Docs] Tiny change in https://docs.modular.com/max/tutorials/magic

[marionegroponzi]

Where is the problem?

https://docs.modular.com/max/tutorials/magic

What can we do better?

The page https://docs.modular.com/max/tutorials/magic#step-5-use-a-nested-package suggests running magic run bash local/zero

but that returns "local/zero: local/zero: cannot execute binary file"

The command should be changed to magic run bash -c local/zero.

Anything else?

You're awesome!