Post-merge doc regen check in main: SDP_Guide.Unix.html/.pdf and
TheSiteDirectory.html (rendered from Server/Unix/p4/common/site/
ReadMe.md) were stale relative to their sources after today's
Merge Down from r26.1.0 (change 33637, which included the
ReadMe.md HMS-link fix). Regenerated. Checked all other tracked
HTML/PDF files too; everything else was either already current or
only differed in embedded PDF timestamp metadata with no real
content change (reverted those).