Update CHANGELOG

CHANGELOG.rst

 Changelog
 =========
 
+`2.0a2`_
+--------
+
+New features
+~~~~~~~~~~~~
+
+* Import absence reasons
+* Import absences
+* Import breaks
+* Import classes
+* Import events
+* Import exported Untis database via MySQL import
+* Import holidays
+* Import lessons
+* Import rooms
+* Import subjects
+* Import substitutions
+* Import supervision areas
+* Import teachers
+* Import time periods
+
+Bugfixes
+~~~~~~~~
+
+* None
+
+Minor changes
+~~~~~~~~~~~~~
+
+* None
+
 `1.0a1`_
 --------
 
@@ -22,3 +53,4 @@ Minor changes
 * Use bootstrap buttons everywhere
 
 _`1.0a1`: https://edugit.org/Teckids/AlekSIS/AlekSIS-App-Untis/-/tags/1.0a1
+_`2.0a2`: https://edugit.org/Teckids/AlekSIS/AlekSIS-App-Untis/-/tags/2.0a2
\ No newline at end of file