prepare for listing bugfixes in whatsnew

closes #283

doc/source/pre/whatsnew/1.4.rst

 What's new in Kwant 1.4
 =======================
 
-This article explains the user-visible changes in Kwant 1.4.0.
-See also the `full list of changes up to the most recent bugfix
-release of the 1.4 series
-<https://gitlab.kwant-project.org/kwant/kwant/compare/v1.4.0...latest-1.4>`_.
-
+This article explains the user-visible changes in Kwant 1.4.0.  Subsequently,
+the user-visible changes for each maintenance release of the 1.4.x series are
+listed (if there were any).
 
 Installation on Microsoft Windows is available via Conda
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