fix(create-nuxt-content-docs): respect npm client answer

[nozomuikuta]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

Resolves: #773

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes (if not applicable, please state why)

Test notes:

• Link my local create-nuxt-content-docs package
• Run npx create-nuxt-content-docs <project_name>
• Select Npm when asked Package manager

As a result, SAO used npm as client.

[pi0]

Thanks!