HPCC-9912 Document LOCAL option on DATASET n TRANSFORM

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9912 Edits based upon review

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9912 Edits based on code review

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9912 edits from review

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
Merge pull request #4950 from JamesDeFabia/HPCC-9912DocumentDATASET_n_TRANSFORM_LOCAL

HPCC-9912 Document LOCAL option for DATASET n TRANSFORM

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>