Shell completion support

[Perdolique]

Description

TAB completion should improve developer experience.

Examples

• vp TAB for vp commands, params and options
• vp run TAB for scripts in the package.json file.

Suggested solution

Since ~/.vite-plus/env is already present, it can be added directly to the file. In this case, only vp upgrade is needed.

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.

[nekomoyi]

I'd like to work on this feature