Adding Hristiyans presentation (#385)

* Adding Hristiyans presentation

* Fixed standing_meetings.yml

Author: HrisShterev

_data/standing_meetings.yml

@@ -3,6 +3,10 @@
   time_cest: "17:00"
   connect: "[Link to zoom](https://princeton.zoom.us/j/97915651167?pwd=MXJ1T2lhc3Z5QWlYbUFnMTZYQlNRdz09)"
   agenda:
+    - title: "Creating teaching materials for C++ and CUDA with xeus-cpp"
+      date: 2026-03-18 15:00:00 +0200
+      speaker: "Hristiyan Shterev"
+      link: "[Slides](/assets/presentations/Hristiyan-Shterev-Teaching-materials-with-xeus-cpp.pdf)"
     - title: "Wrap-Up: Implementing Debugging Support for xeus-cpp"
       date: 2025-11-13 15:00:00 +0200
       speaker: "Abhinav Kumar"