Installation instructions removed

[Diggsey]

This PR removes the instructions for installing on windows 😠 Meanwhile, the build error still links to a non-existent "windows" section in the README.

It looks like you're compiling for MSVC but we couldn't detect an OpenSSL
installation. If there isn't one installed then you can try the rust-openssl
README for more information about how to download precompiled binaries of
OpenSSL:

https://github.com/sfackler/rust-openssl#windows

[ta32]

The docs are available on an old version here
https://docs.rs/crate/openssl-sys/0.9.36

I don't know why they were removed. Were they invalid and no one could maintain them?

These instructions worked for me
#1062 (comment)