[dotnet-suggest] Support for Docker runtime-deps:alpine

[iBicha]

Trying to ship a CLI (self-contained .net app) using Docker image mcr.microsoft.com/dotnet/runtime-deps:6.0.9-alpine3.16-amd64.
The choice of this image is to be as lightweight as possible.

The first problem is that dotnet command is not available to install using
RUN dotnet tool install -g dotnet-suggest.

When using a separate image (like mcr.microsoft.com/dotnet/sdk:6.0.401-alpine3.16-amd64) there's a couple of issues with that:

• /root/.dotnet/tools is not added to the PATH (I guess referencing this issue)
• The second part is that dotnet-suggest does not seem to work at all on alpine (my other guess is we need this PR to land first)
• The last thing is the shim needed. dotnet suggest currently support Bash|PowerShell|Zsh, but I think the default for Alpine is Ash.

Overall, we need a simple way to ship a self-contained .net app, with dotnet-suggest pre-configured on Docker, to reduce the burden to set it up for users.

Thanks

[KathleenDollard]

@baronfel