Add a new section about useful font collections for X11, with
pointers to x11-fonts/* ports for the fonts. It may not be
obvious for new FreeBSD users that just by adding a nice
collection of TTF fonts their X11 desktop experience will
improve a lot.

Inspired by: a post by Dimitris Giakoudis in -questions
Message-Id: <F95AF95EFE11498A947C7EA1A81D007B@titan>