Add entry for the pprint module.
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index 61a9abe..391c241 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -87,6 +87,7 @@
 \input{libimp}
 \input{libni}
 \input{libparser}
+\input{libpprint}
 \input{libsite}
 \input{libbltin}		% really __builtin__
 \input{libmain}			% really __main__