[Docs] Amend hints on versions

docs/admin/10_features.rst

@@ -26,6 +26,9 @@ information from Untis can be imported into AlekSIS:
 * Substitutions, extra lessons, cancellations
 * Events
 
+The Untis integration supports the versioning features of Untis. By default,
+the most recent version of each object is imported.
+
 Currently, the following features are known not to be supported:
 
 * Students, student groups, student choices

docs/admin/20_configuration.rst

@@ -92,7 +92,9 @@ is also already imported when it becomes reelvant.
 
 In general, all tasks will do nothing if there is no matching Untis term.
 
-To use these tasks, you have to add them as periodic tasks.
+To use these tasks, you have to add them as periodic tasks. By default, they will
+import the most recent plan version from Untis. To select a specific version (i.e.
+to import an older snapshot), you can pass the ``version`` argument in the tasks.
 
 How existing data is matched
 ----------------------------