fix(docs): keep reference tables inside the page on a phone

Markdown pipe-tables render as a bare <table> with no scroll container, so any
table wider than about three columns pushed the whole page sideways — 265px of
it on the Colors page at 390px wide.

A small rehype plugin now wraps them in .table-responsive with a tab stop,
exactly like the hand-written tables beside them: the table scrolls inside the
content column and the scrollable region stays keyboard-reachable, which the
axe gate requires. Desktop layout is unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: puikinsh