Add the Labs projects provided in the V10.2.1_191129 zip file.

FreeRTOS-Labs/Demo/FreeRTOS_IoT_Libraries/mqtt/readme.txt

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+See https://freertos.org/mqtt/ for further information.
+
+Contains projects that demonstrate the IoT MQTT library.
+
+- Securing MQTT Communication -
+Internet of Things use cases require MQTT communications to be secured, but secure
+authentication and encryption are not part of the MQTT specification.  It is
+therefore common to use MQTT in combination with Transport Layer Security (TLS).
+TLS encrypts data sent across a network and enables the data's destination to be
+authenticated.  'Server authentication' is when the MQTT client authenticates the
+identity of the MQTT broker.  'Mutual authentication' is when the MQTT broker also
+authenticates the identity of the MQTT client.
+
+
+- Pre-configured MQTT Example Projects -
+The examples contained in subdirectories from here demonstrate the concepts
+described above one at a time.  The first example demonstrates plain text
+(unencrypted) MQTT communication, the second example builds on the first to
+introduce weak server authentication, and the third example builds on the second to
+introduce strong mutual authentication.  Note:  It is our recommendation to always
+use strong mutual authentication in any Internet of Things (IoT) application.  The
+plain text project is only provided to validate MQTT communication can be
+established prior to introducing encryption and authentication, and to allow the
+MQTT packets to be observed using a network packet sniffer such as Wireshark for
+those who wish to do so.  The first two projects are in no way intended to be
+examples suitable for production use.