Add a note about the filter option on the author pages
Add a note about the filter option on the author pages

It relies on our own custom filtering code that is not part of
middleman-blog.  While I was investigating this took me a while to
work out so a pointer would be useful.

unboxed/ubxd_web_refresh,unboxed/unboxed.co,unboxed/ubxd_web_refresh,unboxed/unboxed.co,unboxed/unboxed.co,unboxed/ubxd_web_refresh