Beamer: add allowframebreaks to slide if set in header classes.

It's recommended that your bibliography slide have this
attribute:

    # References {.allowframebreaks}

This causes multiple slides to be created if necessary, depending
on the length of the bibliography.

1 files changed, 10 insertions, 0 deletions

diff --git a/README b/README
index d9b003344..4895f0f52 100644
--- a/README
+++ b/README
@@ -2674,6 +2674,16 @@ using the `-V` option:
 
     pandoc -t beamer habits.txt -V theme:Warsaw -o habits.pdf
 
+Note that header attributes will turn into slide attributes
+(on a `<div>` or `<section>`) in HTML slide formats, allowing you
+to style individual slides.  In Beamer, the only header attribute
+that affects slides is the `allowframebreaks` class, which sets the
+`allowframebreaks` option, causing multiple slides to be created
+if the content overfills the frame.  This is recommended especially for
+bibliographies:
+
+    # References {.allowframebreaks}
+
 Literate Haskell support
 ========================