extend GPU Programming section
Resolves #102 (closed):
- add general information on available GPUs
- add general information on how to use GPUs with Slurm
- extend OpenACC section
- add OpenMP section
- extend CUDA section
- add Performance Analysis section
- remove HMPP section, as HMPP/CAPS seems discontinued & not available on the ZIH system
Edited by Jan Frenzel