Update README.md (#648)

* Update README.md

Update for 2025 cohort starting in september

* Update README.md

---------

Co-authored-by: Alexey Grigorev <alexeygrigorev@users.noreply.github.com>

Author: TillMeineke

README.md

@@ -24,8 +24,9 @@ Master the fundamentals of machine learning, from regression and classification
 
 ## How to Enroll
 
-### 2024 Cohort
-- **Start Date**: September 16, 2024 (17:00 Berlin time)
+### 2025 Cohort
+
+- **Start Date**: September 2025
 - **Register Here**: [Sign up](https://airtable.com/shryxwLd0COOEaqXo)
 - **Stay Updated**: Subscribe to our [Google Calendar](https://calendar.google.com/calendar/?cid=cGtjZ2tkbGc1OG9yb2lxa2Vwc2g4YXMzMmNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ)