Added paragraph about SSE3 support to build-instructions.md.

[osxaudio]

What

Added a small paragraph on how to fix missing SSE3 Support by installing the opemu-linux kernel module.

Why

I just want to save others from going through these two issues: https://github.com/darlinghq/darling/issues/776, https://github.com/darlinghq/darling/issues/882, before arriving at https://github.com/darlinghq/darling/issues/1497 and figuring out the solution by @Mabbs works for them too.

Why like this

Yes build instructions might not be the perfectly correct page for this paragraph, but I didn't find any other “Known Issues Section” and the ZFS problem is also handled here, therefore I think it is not too out of place

Open questions/concerns

Only question, should I add a warning about installing some random kernel module from GitHub ?