[CARBONDATA-1948] Update help document for the change made for CARBONDATA-1929
[CARBONDATA-1948] Update help document for the change made for CARBONDATA-1929

Update help document for the change made for CARBONDATA-1929

This closes #1884

ravipesala/incubator-carbondata,jackylk/incubator-carbondata,manishgupta88/carbondata,ravipesala/incubator-carbondata,zzcclp/carbondata,jatin9896/incubator-carbondata,ravipesala/incubator-carbondata,manishgupta88/carbondata,jatin9896/incubator-carbondata,zzcclp/carbondata,manishgupta88/incubator-carbondata,zzcclp/carbondata,sgururajshetty/carbondata,jackylk/incubator-carbondata,jackylk/incubator-carbondata,manishgupta88/incubator-carbondata,manishgupta88/incubator-carbondata,zzcclp/carbondata,jackylk/incubator-carbondata,manishgupta88/carbondata,sgururajshetty/carbondata,sgururajshetty/carbondata,manishgupta88/carbondata,jatin9896/incubator-carbondata,zzcclp/carbondata,ravipesala/incubator-carbondata,manishgupta88/incubator-carbondata