Fix documentation in client
Fix documentation in client

Commit ba89971a1f20e9a41222d041901926ee3f92eb9c changed Start to Connect, but
this was not updated in the docs which can lead to confusion.

Signed-off-by: Jason Swails <fbb96322dd78528f153a41331f8a93f60dcaefe6@gmail.com>

choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang