Rename page heading to cluster not system

doc.zih.tu-dresden.de/docs/jobs_and_resources/julia.md

-# SMP System Julia
+# SMP Cluster Julia
 
 The HPE Superdome Flex is a large shared memory node. It is especially well suited for data
 intensive application scenarios, for example to process extremely large data sets completely in main

doc.zih.tu-dresden.de/mkdocs.yml

@@ -104,12 +104,12 @@ nav:
     - HPC Resources:
       - Overview: jobs_and_resources/hardware_overview.md
       - CPU Cluster Barnard: jobs_and_resources/barnard.md
-      - CPU Custer Romeo: jobs_and_resources/romeo.md
-      - NVMe Storage: jobs_and_resources/nvme_storage.md
       - GPU Cluster Alpha Centauri: jobs_and_resources/alpha_centauri.md
-      - SMP System Julia: jobs_and_resources/julia.md
-      - GPU System Power9: jobs_and_resources/power9.md
+      - SMP Cluster Julia: jobs_and_resources/julia.md
+      - CPU Custer Romeo: jobs_and_resources/romeo.md
+      - GPU Cluster Power9: jobs_and_resources/power9.md
       - NVIDIA Arm HPC Developer Kit: jobs_and_resources/arm_hpc_devkit.md
+      - NVMe Storage: jobs_and_resources/nvme_storage.md
     - Running Jobs:
       - Batch System Slurm: jobs_and_resources/slurm.md
       - Job Examples: jobs_and_resources/slurm_examples.md