Final call: Table header cells have assigned data cells (d0f69e)

Hi All,

The table rule "Table header cells have assigned data cells (d0f69e)" has
the required approvals and is thus going into a 2 week final call, which
will end on Jan 31, 2020.
https://github.com/act-rules/act-rules.github.io/pull/979

Feedback is welcome during this period.

Best
Jey