add more lsp servers for nvim

nvim/lua/settings/lsp_config/csharp_ls.lua

@@ -0,0 +1,20 @@
+local util = require 'lspconfig.util'
+
+return {
+  default_config = {
+    cmd = { 'csharp-ls' },
+    root_dir = util.root_pattern('*.sln', '*.csproj', '*.fsproj', '.git'),
+    filetypes = { 'cs' },
+    init_options = {
+      AutomaticWorkspaceInit = true,
+    },
+  },
+  docs = {
+    description = [[
+https://github.com/razzmatazz/csharp-language-server
+Language Server for C#.
+csharp-ls requires the [dotnet-sdk](https://dotnet.microsoft.com/download) to be installed.
+The preferred way to install csharp-ls is with `dotnet tool install --global csharp-ls`.
+    ]],
+  },
+}