resolves #64 add support for frame and grid styles on tables
requested to merge RayOffiah/antora-ui-default:#64_The_frame=none_attribute_has_no_effect_on_tables into master
Ready for review, added a few classes to support the AsciiDoc table grid and frame properties in Antora. Didn't go exactly as planned, (I wanted to use the same border-width: 0 that the Asciidoctor docs CSS files used, but ended up being a bit more aggressive to get it working).
Edited by Dan Allen