Add Happy-hour-012 recording

Author: Richard Top

docs/training-events/2025/happy-hours-previous-sessions.md

@@ -11,7 +11,7 @@ Find slides, and video recordings of earlier sessions below.
 **Outline:** Contributing software packages to EESSI
 ([Slides (PDF)](EESSI-happyhour-2025-012-Contributing-software-to-EESSI.pdf), [Recording (YouTube)](https://))
 
-<iframe width="560" height="315" src="https://" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/BYgQlI5mmzs?si=HrQMZa0ckcR_EkQF" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
 
 ### Monday 27 October 2025
 

docs/training-events/2025/happy-hours-sessions.md

@@ -53,7 +53,7 @@ See the full Recordings, slides, and materials here: [Previous Sessions & Videos
 *Topic series: Building on top of EESSI*
 
 
-- 03 November 2025 [Contributing software packages to EESSI](https://)
+- 03 November 2025 [Contributing software packages to EESSI](https://www.youtube.com/watch?v=BYgQlI5mmzs)
 
 - 27 October 2025 [Building on top of EESSI using `buildenv` modules](https://youtu.be/0uwUlM1xqNk)