doc/hgrc.5.txt: deprecate [defaults]
Quoting Matt:
"Defaults are a bad idea. They are deprecated. Don't use them. Don't
recommend them. Forget they existed. Use aliases."
in http://selenic.com/pipermail/mercurial-devel/2009-October/016095.html
.. Common link and substitution definitions.
.. |hg(1)| replace:: **hg**\ (1)
.. _hg(1): hg.1.html
.. |hgrc(5)| replace:: **hgrc**\ (5)
.. _hgrc(5): hgrc.5.html
.. |hgignore(5)| replace:: **hgignore**\ (5)
.. _hgignore(5): hgignore.5.html