Fix changelog update

CHANGELOG.rst

@@ -6,16 +6,16 @@ All notable changes to this project will be documented in this file.
 The format is based on `Keep a Changelog`_,
 and this project adheres to `Semantic Versioning`_.
 
-Unrelease
+Unreleased
 ---------
 
 Changed
 ~~~~~~~
 
-* Reduce the margin to 5mm
-* Set width to 200mm
-* Reduce the space between the header and the heading
-* Display block of absentees as a table
+* Improve the formatting of the print version of the substitution plan
+  * Reduce the page margin.
+  * Reduce the space between the header and the heading.
+  * Display block of absences as a table.
 
 `2.0rc3`_ - 2021-09-24
 ----------------------