initial roslyn configuration

lua/custom/plugins/roslyn.lua

@@ -0,0 +1,8 @@
+return {
+  'seblyng/roslyn.nvim',
+  ---@module 'roslyn.config'
+  ---@type RoslynNvimConfig
+  opts = {
+    -- your configuration comes here; leave empty for default settings
+  },
+}