Add hakken dates for 2025

Reviewed-on: pub-solar/pub.solar#31
Reviewed-by: b12f <b12f@noreply.git.pub.solar>
Co-authored-by: janhaa <janhaa@noreply.git.pub.solar>
Co-committed-by: janhaa <janhaa@noreply.git.pub.solar>

_data/hakken.yml

@@ -1,46 +1,31 @@
 dates:
-  - name: Summer 2024
-    id: summer-2024
-    theme: Hot CPU Summer
-    override_date:
-      start: '2024-08-23'
-      end: '2024-08-25'
+  - name: Winter 2025
+    id: winter-2025
+    theme: Winter Hakken
     location:
       en: Cologne @ [MiOM space](https://miom.space)
       de: Köln @ [MiOM Kreativraum](https://miom.space)
-    description: 
-      en: |
-        Summer is hot and will be getting hotter. CPUs are overheating in the new CO2 normal, can we do better?
 
-        Ideas for projects:
-          * Look for ways to reduce the pub.solar carbon footprint
-          * Create an open source bicycle computer
-      de: |
-        Der Sommer ist heiß und wird immer heißer werden. CPUs überhitzen in dem neuen Normal des CO2, was können wir da besser machen?
-
-        Projekt-Ideen:
-          * Mittel und Wege finden pub.solar nachhaltiger zu gestalten
-          * Einen open source Fahrradcomputer bauen
-
-  - name: Autumn 2024
-    id: autumn-2024
-    theme: Awesome hardware autumn
+  - name: Spring 2025
+    id: spring-2025
+    theme: Spring Hakken
     location:
       en: Cologne @ [MiOM space](https://miom.space)
       de: Köln @ [MiOM Kreativraum](https://miom.space)
-    description: 
-      en: |
-        We need more blinking LEDs.
 
-        Ideas for projects:
-          * Wearable pub.solar LED earrings
-          * LED logo
-      de: |
-        Wir brauchen mehr blinkende LEDs.
+  - name: Summer 2025
+    id: summer-2025
+    theme: Summer Hakken
+    location:
+      en: Cologne @ [MiOM space](https://miom.space)
+      de: Köln @ [MiOM Kreativraum](https://miom.space)
 
-        Projekt-Ideen:
-          * Tragbare pub.solar LED Ohrringe
-          * LED logo
+  - name: Autumn 2025
+    id: autumn-2025
+    theme: Autumn Hakken
+    location:
+      en: Cologne @ [MiOM space](https://miom.space)
+      de: Köln @ [MiOM Kreativraum](https://miom.space)
 
 strings:
   when:
@@ -91,4 +76,4 @@ strings:
     - en: 'November'
       de: 'November'
     - en: 'December'
-      de: 'Dezember'
+      de: 'Dezember'