Resolve "Carry over the data of the first lesson for double (or triple, ...) lessons"

Closes #64 (closed)

aleksis/apps/alsijil/models.py

@@ -107,7 +107,7 @@ class LessonDocumentation(ExtensibleModel):
     )
 
     def _carry_over_data(self):
-        """Carry over data to the next lesson, if exists and data are not already set.
+        """Carry over data to the following lesson periods, if exist and data are not already set.
 
         Can be deactivated using site preference ``alsijil__carry_over``.
         """