Clean up broken installation methods

[cnd]

blocker issue: fsharp/fsharp#889

[ninjarobot]

I'm not so sure about the Gentoo commands, but the Linux commands work for Debian and Ubuntu systems. If anything, we could add msbuild to the list of prerequisite packages, but the mono packages have included it for quite a while. I wouldn't consider the Linux instructions to build from source to be broken though, as they do work with a mono installed from mono-devel or mono-complete.

[cnd]

@ninjarobot I can't find msbuild in mono package (but let keep discussion on blocker issue)

I don't know know about Debian and Ubuntu honestly but I'm fine if you will add remark to instruction that you need to have Debian or Ubuntu to build it, sorry.

[lenadroid]

@ninjarobot do you think we can add a note based on the latest @cnd's comment? /cc @ReedCopsey

[ninjarobot]

@lenadroid there's ongoing discussion to try to get msbuild on gentoo so mono and fsharp can be deployed on gentoo as well. In the meantime, I'd rather this PR be adjusted to just only remove the gentoo part of the instructions in favor of a note that it can be built and deployed on Debian and Red Hat derivatives with the current instructions. @cnd would you be OK adjusting your PR with that in mind for now?

[cnd]

@ninjarobot no, you should rewrite install from sources for rhel and debian too and specify which binary packages users should install (with bundled msbuild) and remove build mono from source part

[voronoipotato]

I just installed .net core on fedora the other day, so perhaps I can look at dnf history and my bash history to see what steps I needed to take.

[dsyme]

Closing as this has been re-written