Completion support for commands and options in PowerShell and PowerCore

[lewoudar]

Issues

Like the title said, I want to implement completion capabilities on ws. I started PR #6 for this purpose. Unfortunately
when trying on my Windows 10 laptop, I have two / three problems:

• First, for an unknown reason, when spawning a virtualenv with poetry (my package manager)
  shellingham detects the shell as cmd 🤨. I guess it is not really important
  since when I created a binary wheel and installed it locally, I don't have this issue anymore.
• Second, and the real one, the command install-completion installed the completion script, but... nothing happens. 😢
• Also, not sure, it is really important, but it seems like calling install-completion again creates a weird error. Not
  sure if it is due to my configuration or the fact that I tried to manipulate my user profile to test different setups
  and also, in practice there is no need to call install-completion twice if it works correctly.

Alternatives

click-completion

There is a community package click-completion I used to use a few
years ago but seems a little outdated now.

typer

Typer is a great package based on click, but I found it (personal taste may be) not
convenient to extend it with community packages like those of click-contrib.

What's next?

It will be interesting if someone tests my PR on his laptop to see if autocompletion works correctly. Maybe it is just
my shell configuration which has an issue?
But if it does not work on someone else computer, I'll definitely need help because it is not a subject I master.

[Zedai00]

Okay I've tried installing using pip install and the completion doesn't work