HPCC-10756 DOCS:HTML on PORTAL

Fix HPCC-10756 DOCS:HTML on PORTAL
Fix source code to generate HTML
more consistent with our style for
the Language Reference Manual.

Signed-off-by: g-pan <greg.panagiotatos@lexisnexis.com>
Merge pull request #5316 from g-pan/H0756-LR_topix

HPCC-10756 DOCS:HTML on PORTAL

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>