Give the section on PEP 263 a more meaningful title, so readers will

be able to locate this information without knowing the PEP number.

Doc/whatsnew/whatsnew23.tex

@@ -282,7 +282,7 @@ and Tim Peters, with other fixes from the Python Labs crew.}
 
 
 %======================================================================
-\section{PEP 263: \label{section-encodings}}
+\section{PEP 263: Source Code Encodings \label{section-encodings}}
 
 Python source files can now be declared as being in different
 character set encodings.  Encodings are declared by including a