feat(pkgs): Install omnisharp and friends

emacs.nix

@@ -96,6 +96,7 @@ in emacsWithPackages(epkgs:
     multiple-cursors
     nginx-mode
     nix-mode
+    omnisharp
     paredit
     password-store
     pg

packages.nix

@@ -57,6 +57,7 @@ in {
     curl
     direnv
     dnsutils
+    dotnet-sdk
     evince
     exa
     extremetuxracer
@@ -81,6 +82,7 @@ in {
     lxappearance-gtk3
     manpages
     maven
+    mono
     mq-cli
     msmtp
     ngrok
@@ -115,6 +117,8 @@ in {
     units
     unzip
     vlc
+    wine
+    winetricks
     xclip
     xfce.xfce4-screenshooter