feat: rework to modular

modules/base/shell.nix

@@ -0,0 +1,20 @@
+{ ... }:
+{
+  programs.bash.enable = true;
+
+  programs.zsh = {
+    enable = true;
+    autocd = true;
+    enableCompletion = true;
+    shellAliases = {
+      l = "ls -CF";
+      la = "ls -A";
+      ll = "ls -alF";
+    };
+  };
+
+  programs.direnv = {
+    enable = true;
+    nix-direnv.enable = true;
+  };
+}