Docs for vp commands sometimes unclear

[Anoesj]

Description

While many terminal commands are clear, some can be documented a bit better:

• vp env default
  • Document usage with args (vp env default <version>?)
• vp env pin -> vp env pin <version>
  • Bonus: without <version>, it could prompt to: a) pin the current global Node version locally; b) pin Node LTS
• vp env use
  • Can be ran with or without args, document usage with args too: vp env use <version>
  • Document vp env use --unset
• vp env exec -> vp env exec [--node <version>] <command> [args...]

There are probably more improvements to be made here, but these are the ones that I ran into.

Suggested solution

See above

Alternative

No response

Additional context

No response

Validations

• Read the Contributing Guidelines.
• Confirm this request is for Vite+ itself and not for Vite, Vitest, tsdown, Rolldown, or Oxc.
• Check that there isn't already an issue requesting the same feature.

[cpojer]

@Anoesj Can you send a PR with your proposal?