add seealso referring to site module doc where people can learn how to

Skip Montanaro · Skip Montanaro · commit 8a79727b5319 · 2002-03-27T17:29:50.000Z
extend sys.path using .pth files.
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
@@ -482,3 +482,9 @@ \section{\module{sys} ---
   Python.
   Availability: Windows.
 \end{datadesc}
+
+
+\begin{seealso}
+  \seemodule{site}
+    {This describes how to use .pth files to extend \code{sys.path}.}
+\end{seealso}
