Adding license guidance.

ueforth/site/ESP32forth.html

@@ -53,6 +53,40 @@ limitations under the License.
   - Complete Unprocessed Source Code (under ueforth/)
 </p>
 
+<h2>License</h2>
+
+<p>
+<b>
+NOTE: Although Esp32forth is licensed under Apache 2.0,
+please be aware that binaries built with the Arduino IDE (such as ESP32forth) include
+components and libraries under
+<a target="_blank" href="https://github.com/arduino/Arduino/blob/master/license.txt">other additional licenses</a>.<br/>
+The ESP32 plugin for Arduino is also under a
+<a target="_blank" href="https://github.com/espressif/arduino-esp32/blob/master/LICENSE.md">different license</a>.<br/>
+Additionally, the ESP32 toolchain used by Arduino, contains further components under
+<a target="_blank" href="https://docs.espressif.com/projects/esp-idf/en/latest/esp32/COPYRIGHT.html">other licenses</a>.<br/>
+<u>Be sure to consult a lawyer before using for comercial purposes.</u>
+</b>
+</p>
+
+<hr/>
+
+<pre>
+Copyright 2021 Bradley D. Nelson
+
+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
+
+    <a target="_blank" href="http://www.apache.org/licenses/LICENSE-2.0">http://www.apache.org/licenses/LICENSE-2.0</a>
+
+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.
+</pre>
+
 <h2>Install</h2>
 
 <p>