Update megSAP/GSvar docu

[marc-sturm]

TODO:

• hardware requirements GSvarServer, NGSD, Compute nodes ...
  • CPU
  • RAM
  • /tmp/
  • storage in general
• backup NGSD
• certificates (GSvarServer, SQL server)
• analysis steps SR:
  • requirements/interactions
  • CNVs >10
• analysis steps SR:
  • requirements/interactions
  • CNVs >10