Add: optional DoScript one-click installer for Windows (PortablePython)

[TheServer-lab]

Hi! 👋

I noticed Windows setup currently requires several manual steps
(download, extraction, ensurepip, PATH setup).

I created a small automated installer script that reduces this
process to one command and verifies that Python + pip work correctly.

This is completely optional and does not change existing behavior,
but may help beginners get started faster.

Happy to modify or remove if not useful.
Thanks for the great project!

Files added:

• doscript-installer/install.do
• doscript-installer/README.md

Notes:

• The installer uses DoScript commands (download, unzip, path add, etc.)
• It is intentionally small and optional — it won't change the codebase unless a user runs it locally.
• If you'd prefer a different default install path, wording, or behavior (overwrite policy), I'm happy to adjust.

— DoScript contributor