Write out feed.atom files for each tag.
Write out feed.atom files for each tag.

Signed-off-by: Armin Ronacher <51e1b983df8328b92ad653ca9129d9a11178303a@active-4.com>

oddbird/rstblog,azbshiri/rstblog,azbshiri/rstblog,mitsuhiko/rstblog,oddbird/rstblog