use strict;
use warnings;
use Text::CSV_XS;

my %values;
my $key;
my @keys;
while (<DATA>) {
    chomp;
    m/^\s*#/ and next; # Skip comment
    m/^\s*$/ and next; # Skip empty lines
    if (m/^\s* (.+?) \s*:\s* $/x) {
        $key = $1;
        push @keys, $key;
        next;
        }
    s/^\s+//;
    s/\s+$//;
    push @{ $values{$key} }, $_;
    }

my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, eol => "\n" });
$csv->print (*STDOUT, \@keys);
$csv->print (*STDOUT, [ map { "@$_" } @values{@keys} ]);