Issue with page src/pages/start/4.nix-develop.mdx - Funny Joke

[nielsegberts]

The user is asked to run

nix develop "github:DeterminateSystems/zero-to-nix#example"

And then

nix develop "github:DeterminateSystems/zero-to-nix#hook"

Right after that the funny joke is mentioned:

Nix development environments support environment variables as well. Run echo $FUNNY_JOKE to access a (hilarious) value that's available only in the Nix environment.

However the hook environment does not have the funny joke only the example environment does. And if the user is expected to be two environments deep now (because exit is not explained until later), the explanation of exit is not sufficient because after running exit once (out of the hook environment) the joke is still accessible even though the explanation says it shouldn't.

This was introduced in this very recent commit:
1acb39d