docs: Use a line length of max 78 characters

Author: nfnty

doc/python-syntax.txt

@@ -1,7 +1,7 @@
 *python-syntax.txt* Python syntax highlighting
 
-===============================================================================
-Introduction                          *python-syntax* *ft-python-syntax* *python.vim*
+==============================================================================
+Introduction                         *python-syntax* *ft-python-syntax* *python.vim*
 
 This is an enhanced version of the original Vim 6.1 Python syntax highlighting
 `python.vim` by Neil Schemenauer.
@@ -33,8 +33,8 @@ Features
 Folding is done by the plugin SimpylFold
 (https://github.com/tmhedberg/SimpylFold).
 
-===============================================================================
-Configuration                                       *python-syntax-configuration*
+==============================================================================
+Configuration                                      *python-syntax-configuration*
 
 Option variables
 ----------------