https://github.com/OmniSharp/Omnisharp-vim
https://medium.com/@kpereksta/setting-up-a-c-development-environment-with-vim-on-debian-ea42d5b810
Install .NET Core on Debian
You can find the install instructions for most linux distributions here: https://docs.microsoft.com/en-us/dotnet/core/install/linux
On debian specifically here: https://docs.microsoft.com/en-us/dotnet/core/install/linux-debian