Refactored file structure to make more sense, made default.nixes less verbose

modules/sys/software/nixvim/plugins/cmp.nix

@@ -0,0 +1,12 @@
+{
+  programs.nixvim = {
+    plugins.cmp = {
+      autoEnableSources = true;
+      settings.sources = [
+        {name = "nvim_lsp";}
+        {name = "path";}
+        {name = "buffer";}
+      ];
+    };
+  };
+}