Add note on custom arguments for vampirserver

doc.zih.tu-dresden.de/docs/software/vampir.md

@@ -74,7 +74,7 @@ Submitting slurm 30 minutes job (this might take a while)...
 ```
 
 This way, a job with a timelimit of 30 minutes and default resources is submitted. This might fit
-your needs. If not, please feel free to request a customized job running VampirServer, e.g.
+your needs. If not, please feel free to request a **customized job** running VampirServer, e.g.
 
 ```console
 marie@login$ vampirserver start --ntasks=8 -- --time=01:00:00 -- --mem-per-cpu=3000M --partition=romeo
@@ -82,7 +82,12 @@ Launching VampirServer...
 Submitting slurm 01:00:00 minutes job (this might take a while)...
 ```
 
-Above automatically allocates its resources via the respective batch system. If you want to start
+The above `vampirserver` command automatically allocates its resources via the respective batch system
+(, i.e. [Slurm](../jobs_and_resources/slurm.md) on ZIH systems).
+Please note that custom arguments which should be passed to the batch system, need to be prefixed
+with `--`.
+
+If you want to start
 
 VampirServer without a batch allocation or from inside an interactive allocation, use