Merge pull request #25 from OpenRailAssociation/add-videos

feat: add more videos

Author: OebbJan

content/organization/participation.md

@@ -25,4 +25,10 @@ As a **participant**, you actively contribute to the hackathon by forming a team
 If you want to get a feeling for what to expect at the Hack4Rail in Vienna, check out these videos of the previous years:
 
 ### Hack4Rail 2025 - Bern
-{{< youtube F_wM7T0TsnQ >}}
+{{< youtube F_wM7T0TsnQ >}}
+
+### Dreiländerhack 2024 - Berlin
+{{< youtube SmvpGrI1P9w >}}
+
+### Dreiländerhack 2023 - Wien
+{{< youtube mCjkUJ-Zah4 >}}