Update docs for bool changes by Guido around April 6
diff --git a/Doc/lib/libchunk.tex b/Doc/lib/libchunk.tex
index c580c77..8e2a494 100644
--- a/Doc/lib/libchunk.tex
+++ b/Doc/lib/libchunk.tex
@@ -78,7 +78,7 @@
 the \method{close()} method has been called.
 
 \begin{methoddesc}{isatty}{}
-Returns \code{0}.
+Returns \code{False}.
 \end{methoddesc}
 
 \begin{methoddesc}{seek}{pos\optional{, whence}}