[FEATURE] Document a supported Windows installation path

Summary

Strix publishes a Windows executable and Windows wheel, but the quick start does not explain the supported native Windows setup

The main installation example uses a Bash installer

The installer recognizes Windows only under MINGW, MSYS, or Cygwin, which does not tell PowerShell users what to do

Questions a Windows user has to answer alone

A Windows user currently has to guess between these options

• Native PowerShell with pipx
• The standalone Windows zip
• Git Bash
• WSL
• Docker Desktop with Linux or Windows containers

The project already has a plausible native route through pipx install strix-agent, so the issue is support clarity rather than the absence of any Windows installation path

Suggested page flow

1. Start with the recommended PowerShell installation method
2. Cover the standalone zip if it is supported
3. Name the required shell, Python version, and Docker Desktop container mode
4. Explain when WSL is required or preferred
5. End with one verification command and the known Windows limitations

A PowerShell user should be able to install Strix, choose the right Docker configuration, and verify the executable without translating Bash commands

The same page should make the native Windows, WSL, and CI support boundaries clear