Update NEXT_Quickstart_Under_30_Seconds.md

Author: TimGoTheCreator

NEXT_Quickstart_Under_30_Seconds.md

@@ -11,6 +11,7 @@ This quickstart shows how to build and run a minimal simulation using the **NEXT
 - C++ compiler (Clang, GCC, or MSVC)
 - Python 3 (for example input generation)
 - OpenMP (for Multi-Threadding)
+- HDF5
 
 ---