- Introduce <tablehead> element
- While considering text-align, I noticed we do not take RTL languages
into account. A CSS rule 'html[dir=ltr] th' was added, which does
nothing at the moment. We should look into directionality.
Change-Id: Ib59aa0c508529c0beaa35542d96bd5cc1aa4db29
Reviewed-on: https://gerrit.libreoffice.org/c/help/+/133114
Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>