HPCC-10834 DOCS:Stnd use of Thor,Roxie

HPCC-10834 DOCS:Stnd use of Thor,Roxie
Standardize usage of Thor, Roxie, and hThor in the docs.

Signed-off-by: g-pan <greg.panagiotatos@lexisnexis.com>
Merge pull request #5393 from g-pan/H10834-StdThor

HPCC-10834 DOCS:Stand. use of Thor,Roxie

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>