Add some chapter introductions (not linked into the LibRef yet)
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+\chapter{Interprocess Communication and Networking}
+\label{ipc}
+
+The modules described in this chapter provide mechanisms for different
+processes to communicate.
+
+Some modules only work for two processes that are on the same machine,
+e.g. \module{signal} and \module{subprocess}. Other modules support
+networking protocols that two or more processes can used to
+communicate across machines.
+
+The list of modules described in this chapter is:
+
+\localmoduletable