Documentation changelog

From v7.1 to v7.2

• Added references to the new XBee ZigBee 3 radio

• Deleted references to the discontinued RS-232, GPRS+GPS and 3G modules

• Added references to the new NB-IoT / Cat-M radio

From v7.0 to v7.1

• XBee-PRO ZigBee was discontinued. Document updated for the new XBee ZigBee S2D module.

• Added a new section to show the user how to connect the module to Waspmote