Added instruction to install git using Nix/on NixOS
Added instruction to install git using Nix/on NixOS

mosoft521/gitscm-next,git/git-scm.com,Mokolea/git-scm.com,git/git-scm.com,git/git-scm.com,jasonlong/git-scm.com,Mokolea/git-scm.com,mosoft521/gitscm-next,jasonlong/git-scm.com,jasonlong/git-scm.com,git/git-scm.com,jasonlong/git-scm.com,mosoft521/gitscm-next,Mokolea/git-scm.com,Mokolea/git-scm.com,mosoft521/gitscm-next