lsp: elixir added nextls for it to work and also changed from custom to built in formatter

config/plugins/lang/elixir.nix

@@ -2,16 +2,11 @@
 {
   plugins = {
     lsp.servers.elixirls.enable = true;
+    lsp.servers.nextls.enable = true; # idk probably needed for elixirls
 
     conform-nvim.settings = {
       formatters_by_ft = {
-        elixir = [ "elixir" ];
-      };
-
-      formatters = {
-        elixir = {
-          command = "${pkgs.elixir}/bin/mix format";
-        };
+        elixir = [ "mix" ];
       };
     };
 
@@ -23,4 +18,3 @@
 
   };
 }
-