[Xiph-Advocacy] Newest planet links go to Xiph.Org front page automatically now

I made a quick change to the Xiph.Org front page that a few people
have suggested now over the past few years; the top few blog posts
aggregated by Planet Xiph now appear as a five-item teaser list near
the top of the Xiph.Org home page.  The idea is both to get some more
live content on the front page (with relatively low effort) as well as
to draw more attention to both the Planet and our developer community.

Comments and feedback welcome.

Monty