Add nvim-lazy submodule and add plugin configuration.

pkgsets/nvim/kanagawa-nvim.nix

@@ -0,0 +1,23 @@
+{
+  lib,
+  config,
+  ...
+}:
+
+lib.mkIf (lib.elem "nvim::kanagawa-nvim" config.machine.pkgs) {
+  programs.nvim-lazy.lazyPlugins = [
+    {
+      dir = vPlug: vPlug.kanagawa-nvim;
+      priority = 1000;
+      config = # lua
+        ''
+          function()
+            require('kanagawa').setup({
+              transparent = true,
+            })
+            vim.cmd([[colorscheme kanagawa-wave]])
+          end
+        '';
+    }
+  ];
+}