Change shell command to default

What does this Merge Request do?

The current instruction show a cd instruction that uses the custom directory instead of the default directory which is gitlab-development-kit. It's possible this was intentional since the instructions also indicate how to create a directory with a custom name, but I think is better to stick with the defaults in the provided instructions.

Merge Request checklist

• Tests added for new functionality. If not, please raise Issue to follow-up.
• This change is backward compatible. If not, please include steps to communicate to our users.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.