🚀 go-pugleaf

A tbl problem has been found with centering a heading over a pair of
columns, where the items in the columns themselves are centered or
numeric and the title is wider than the other data in the columns.
(I.e. the widths of the columns need to be enlarged to make the
title fit.)  The extra width needed to make the title fit all gets
added to the second column, instead of being evenly distributed
among the columns.  This messes things up.

This is clearly a tbl bug.  I don't really have a fix for it:  having
worked on the insides of tbl before, I'm not keen on tackling it.
Individual tables can be kludged adequately by giving an explicit width
for the first of the problem columns.

It is possible that this problem crops up in broader circumstances
than the ones I have described above;  I have not investigated it
exhaustively.