Correct header default.

- The <html> tag was not where it was supposed to be. Coding after
work certainly isn't conducive to very good results.

- The <!DOCTYPE> tag was useless in that context, since it doesn't
get parsed in my (highly simplistic) SAX-parsing program. I can
insert it when generating the output files, anyway, so it's not
much of a loss.

Signed-off-by: Weland Treebark <weland@durandal.my.domain>