build: add script to list the top-level namespaces

tools/scripts/top_level_namespaces

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+#
+# @license Apache-2.0
+#
+# Copyright (c) 2023 The Stdlib Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Finds top-level namespaces.
+
+
+# VARIABLES #
+
+# Determine root directory:
+root_dir="$(git rev-parse --show-toplevel)"
+
+# Define the project source code directory:
+base_dir="${root_dir}/lib/node_modules"
+
+
+# FUNCTIONS #
+
+# Finds packages.
+main() {
+	local pkgs
+
+	pkgs=$(find "${base_dir}" -mindepth 2 -maxdepth 2 -type d | sort | sed "s%^${base_dir}\\/%%");
+	echo "${pkgs}"
+}
+
+# Run main:
+main