Add '~/.pause' description to tutorial pod.

I believe Minilla will become standard tool for releasing to CPAN, because it is less-configuration and easy to use for Perl newbies.
I understand it is the must-have-knowledge for CPAN authors that ".pause" file is required for releasing to CPAN by many release tools nowadays, but I think that knowledge is too concealed for newbies.
IMHO, at lease the pointer to CPAN::Upload would be present in the tutorial document.