Document supported OS versions

[Thomasdezeeuw]

Currently there is no explicit documentation on what versions of OSes are supported. We should create such a documentation and keep it up-to-date.

[Thomasdezeeuw]

#124 requires at least Windows 7 SP1 or Windows Server 2008 R2 with SP1.

[Thomasdezeeuw]

Since Microsoft dropped support for Window 8 since 2023-01-10, I think so can we.

[takkuumi]

Since Microsoft dropped support for Window 8 since 2023-01-10, I think so can we.

Maintains consistent compatibility with rust future-windows-compatibility

[Thomasdezeeuw]

Maintains consistent compatibility with rust future-windows-compatibility

Fine as well. We can dropped support for Windows < 10 when we drop support for rustc < 1.76.

[Thomasdezeeuw]

We have some docs in the readme now: https://github.com/rust-lang/socket2?tab=readme-ov-file#os-support, we're mostly matching whatever rustc supports (or at least we try to).