added nixd lsp to helix

hosts/lolcathost/default.nix

@@ -200,6 +200,11 @@ in {
     tldr
     btop
 
+    # TODO: once upgraded past Nix-24.07 this line won't be necessary (I think)
+    #       helix will support nixd by default
+    # SOURCE: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md#Helix
+    nixd # lsp for nix
+
     # Pretty necessary
     git
     brightnessctl