HPCC-10792 Document Relative Import syntax

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-10792 Edit based upon review

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
Merge pull request #6082 from JamesDeFabia/10792_RelativeImportDocs

HPCC-10792 Document Relative Import syntax

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>