docs: add Windows install guide

[fengfeng-zi]

Closes #2

• add a focused newcomer-friendly Windows install guide
• explain Releases vs source workflow
• keep the change documentation-only

[TheNorthStarYang]

Thanks for the contribution! The Windows install guide is helpful and the content looks generally aligned with the project direction.

However, we’re trying to avoid adding separate platform-specific full install guides under the top-level docs/ directory, because it can create multiple sources of truth and make the documentation harder to maintain over time.

For this repository, we’d like to keep:

• docs/installation.md as the repo-level install/build entry point
• platforms/windows/README.md as the Windows platform overview and main Windows entry point
• module-level README files under platforms/windows/ for detailed Windows component instructions

So instead of adding a new docs/install-windows.md, could you please update the existing docs by either:

1. adding a short Windows entry/link in docs/installation.md, or
2. improving/linking to platforms/windows/README.md for the detailed Windows instructions?

This is mainly about keeping the documentation structure clean and avoiding doc drift. Thanks again for helping improve the project!

For now, I’ll hold off on merging this PR until the Windows guide is moved or consolidated into the existing documentation structure.

[fengfeng-zi]

Addressed. I removed docs/install-windows.md and folded the Windows install guidance back into the existing docs structure by keeping docs/installation.md as the repo-level entry and updating platforms/windows/README.md to point to the Windows module READMEs. Kept the change minimal and did not duplicate the module-level build details in a new top-level page.