Add changelog entry

Signed-off-by: Cedric Willekens <c.s.willekens@student.tudelft.nl>

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Sort and add filters for labs on the lab listing page. [@wpolet](https://gitlab.ewi.tudelft.nl/wpolet)
 - Allow teachers to upload CSV files to add participants. [@cedricwilleken](https://gitlab.ewi.tudelft.nl/cedricwilleken)
 - Add admin overview page for ongoing sessions [@cedricwilleken](https://gitlab.ewi.tudelft.nl/cedricwilleken)
+- Add calendar for student overview [@cedricwilleken](https://gitlab.ewi.tudelft.nl/cedricwilleken)
 
 ### Changed