feat: import all base configs in darwin

feat: change darwin's default shell to nushell
feat: update starship's config

home/base/starship.nix

@@ -10,6 +10,15 @@
         success_symbol = "[›](bold green)";
         error_symbol = "[›](bold red)";
       };
+      aws = {
+        symbol = "🅰 ";
+      };
+      gcloud = {
+        # do not show the account/project's info
+        # to avoid the leak of sensitive information when sharing the terminal
+        format = "on [$symbol$active(\($region\))]($style) ";
+        symbol = "🅶 ️";
+      };
     };
   };
 }