re-organize nixvim

programs/nixvim/plugins/lsp/formatting.nix

@@ -0,0 +1,19 @@
+{ ... }:
+
+{
+  programs.nixvim = {
+    # Diagnostics display
+    diagnostic.settings.virtual_text = true;
+
+    plugins = {
+      # Auto-format on save
+      lsp-format = {
+        enable = true;
+        lspServersToEnable = "all";
+      };
+
+      # Sane defaults for all servers
+      lspconfig.enable = true;
+    };
+  };
+}