Use funcdesc instead of classdesc to be consistent with out sections.

Doc/lib/libdatetime.tex

@@ -133,11 +133,12 @@ object
 
 \subsection{\class{timedelta} Objects \label{datetime-timedelta}}
 
-\begin{classdesc}{timedelta}{days=0, seconds=0, microseconds=0,
-                            milliseconds=0, minutes=0, hours=0, weeks=0}
 A \class{timedelta} object represents a duration, the difference
 between two dates or times.
 
+\begin{funcdesc}{timedelta}{days=0, seconds=0, microseconds=0,
+                            milliseconds=0, minutes=0, hours=0, weeks=0}
+
     All arguments are optional.  Arguments may be ints, longs, or floats,
     and may be positive or negative.
 
@@ -177,8 +178,7 @@ between two dates or times.
 >>> (d.days, d.seconds, d.microseconds)
 (-1, 86399, 999999)
 \end{verbatim}
-
-\end{classdesc}
+\end{funcdesc}
 
 Class attributes are: