added a few more plugins, got cmp+luasnip working.

LSP is the last major milestone now.

nix/nvim/treesitter/rainbow-delimiters.nix

@@ -0,0 +1,20 @@
+{
+  configs,
+  pkgs,
+  ...
+}: {
+  programs.nixvim = {
+    plugins.rainbow-delimiters = {
+      enable = true;
+      highlight = [
+        "RainbowDelimiterYellow"
+        "RainbowDelimiterBlue"
+        "RainbowDelimiterOrange"
+        "RainbowDelimiterGreen"
+        "RainbowDelimiterViolet"
+        "RainbowDelimiterCyan"
+        # "RainbowDelimiterRed"
+      ];
+    };
+  };
+}

nix/nvim/treesitter/treesitter.nix

@@ -0,0 +1,22 @@
+{
+  configs,
+  pkgs,
+  ...
+}: {
+  programs.nixvim = {
+    plugins.treesitter = {
+      enable = true;
+      folding = true;
+      indent = true;
+      nixvimInjections = true;
+    };
+    plugins.treesitter-context.enable = true;
+    plugins.indent-blankline.enable = true;
+    extraPlugins = [
+      pkgs.vimPlugins.treesj
+    ];
+  };
+  imports = [
+    ./rainbow-delimiters.nix
+  ];
+}