Documented the '@update' statement in the reference guide
Documented the '@update' statement in the reference guide

Change-Id: Iadeac6e44bef72c27b9b1e3f6a864a24b9771c46
Signed-off-by: Botond Baranyi <32956a780e0ba5b1eeab12cc9cf2331e8093c5b1@ericsson.com>

BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core,BotondBaranyi/titan.core