Added a description for the "for" operator used with sequences.
Added a description for the "for" operator used with sequences.

miyurud/siddhi,minudika/siddhi,mohanvive/siddhi,codemogroup/siddhi,nadundesilva/siddhi,ksdperera/siddhi,ksdperera/siddhi,slgobinath/siddhi,ramindu90/siddhi,suhothayan/siddhi,suhothayan/siddhi,dilini-muthumala/siddhi,minudika/siddhi,ramindu90/siddhi,gokul/siddhi,grainier/siddhi,gokul/siddhi,ChariniNana/siddhi,sajithshn/siddhi,codemogroup/siddhi,tishan89/siddhi,tishan89/siddhi,wso2/siddhi,slgobinath/siddhi,ChariniNana/siddhi,miyurud/siddhi,mohanvive/siddhi,grainier/siddhi,dilini-muthumala/siddhi,nadundesilva/siddhi,sajithshn/siddhi,wso2/siddhi