Add docs for heapq.py.
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index d87a1cf..671c106 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -120,6 +120,7 @@
 \input{librandom}
 \input{libwhrandom}
 \input{libbisect}
+\input{libheapq}
 \input{libarray}
 \input{libcfgparser}
 \input{libfileinput}