powershell always runs with --NoProfile

Hi,

powershell gets always invoked with `-NoProfile` option. This makes persisting PATH and other changes, say, after installing packages with Chocolatey, very difficult (have to repeatedly re-set PATH or run a set-up script for every `run`, instead of saving everything needed to a script that would get run by the profile mechanism)

Do you think this can be changed, or allowed to be changed in shell spec per job?

Start by reviewing how PowerShell is invoked with `-NoProfile` and how the shell spec per job is documented in this repository. Determine whether profile loading can be enabled or configured, then document the supported behavior and verify the example matches the Windows build setup.

Written by the indexing model from the issue text.