shell: feature comparison table from uniq-faq

shell: feature comparison table from uniq-faq

Page copied from browser.plp with unneeded features removed.
Include initialised with data from usenet unix-faq/shell/shell-differences
v1.17 (1997-07-13) by Brian Blackmore:

perl -wE'
	use Data::Dump "pp";
	use List::MoreUtils "mesh";
	while (<>) { last if s/^ +// }  # to table start
	my @cols = split /\s+/;
	while (<>) {
		chomp;
		$_ or last;
		my ($title, $support) = split /  +/, $_, 2;
		my @support = split / +/, $support;
		push @rows, {
			title => $title,
			support => { mesh(@cols, @support) },
		};
	}
	print pp(\@rows);
'