fix: shell dry-run output should be runable

[lalyos]

I've redirected the output of runme run --dry-run into a file.
The code block was of bash type and the file nicely starts with shebang:

#!/usr/local/bin/bash

// run in "/Users/lalyos/somedir"

set -e -o pipefail
echo hello

the run in "dir" line supposed to be a comment, but the syntax doesn't fit shell syntax.

[adambabik]

Good catch! Thanks for the contribution, LGTM!

[adambabik]

@lalyos it seems that this PR is out of date. Could you rebase it on the main branch?

[lalyos]

@adambabik rebased

[sourishkrout]

This change was included in https://github.com/stateful/runme/releases/tag/v3.11.0, @lalyos.