[clreq] Add page format in Glossary? (#282)

xfq has just created a new issue for https://github.com/w3c/clreq:

== Add page format in Glossary? ==
In https://w3c.github.io/clreq/#type_area :

> First, prepare a template of the page format, which determines the basic appearance of document pages.

Maybe we should add a Glossary entry to explain what page format is.

jlreq has one: https://w3c.github.io/jlreq/#term.page-format

Please view or discuss this issue at https://github.com/w3c/clreq/issues/282 using your GitHub account