New fixes to VIM C# configurations.

vim/cs.vim

@@ -5,6 +5,25 @@
 let g:OmniSharp_server_stdio = 1
 let g:OmniSharp_server_use_mono = 1
 
+" Don't autoselect first omnicomplete option, show options even if there is only
+" one (so the preview documentation is accessible). Remove 'preview', 'popup'
+" and 'popuphidden' if you don't want to see any documentation whatsoever.
+" Note that neovim does not support `popuphidden` or `popup` yet:
+" https://github.com/neovim/neovim/issues/10996
+if has('patch-8.1.1880')
+  set completeopt=longest,menuone,popuphidden
+  " Highlight the completion documentation popup background/foreground the same as
+  " the completion menu itself, for better readability with highlighted
+  " documentation.
+  set completepopup=highlight:Pmenu,border:off
+else
+  set completeopt=longest,menuone,preview
+  " Set desired preview window height for viewing documentation.
+  set previewheight=5
+endif
+
+" Tell ALE to use OmniSharp for linting C# files, and no other linters.
+let g:ale_linters = { 'cs': ['OmniSharp'] }
 
 augroup omnisharp_commands
   autocmd!

vim/plugins.vim

@@ -13,6 +13,7 @@ Plugin 'scrooloose/nerdtree'
 Plugin 'airblade/vim-gitgutter'
 Plugin 'bf4/vim-dark_eyes'
 Plugin 'OmniSharp/omnisharp-vim'
+Plugin 'dense-analysis/ale'
 Plugin 'jnurmine/Zenburn'
 
 " All of your Plugins must be added before the following line