Switch to side-by-side view

--- a/src/doc/user/Makefile
+++ b/src/doc/user/Makefile
@@ -7,7 +7,7 @@
 
 DOC?= usermanual
 LANGCODE?= en_US.ISO_8859-1
-FORMATS?= html txt html-split
+FORMATS?= html txt html-split pdf
 JADEFLAGS+=	-V %generate-article-toc%
 
 # The purpose for this is to replace the FreeBSD file which contains the