Doc: Shorten sections titles to cluster names

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

@@ -41,7 +41,10 @@ users and the ZIH.
     - Further information on the usage is documented on the site
       [Export Nodes](../data_transfer/export_nodes.md)
 
-## Barnard - Intel Sapphire Rapids CPUs
+## Barnard
+
+The cluster **Barnard** is a general purpose cluster by Bull. It is based on Intel Sapphire Rapids
+CPUs.
 
 - 630 diskless nodes, each with
     - 2 x Intel Xeon Platinum 8470 (52 cores) @ 2.00 GHz, Multithreading enabled
@@ -49,7 +52,10 @@ users and the ZIH.
 - Hostnames: `n[1001-1630].barnard.hpc.tu-dresden.de`
 - Login nodes: `login[1-4].barnard.hpc.tu-dresden.de`
 
-## Alpha Centauri - AMD Rome CPUs + NVIDIA A100
+## Alpha Centauri
+
+The cluster **Alpha Centauri** (short: **Alpha**) by NEC provides AMD Rome CPUs and NVIDIA A100 GPUs
+and designed for AI and ML tasks.
 
 - 34 nodes, each with
     - 8 x NVIDIA A100-SXM4 Tensor Core-GPUs
@@ -84,7 +90,9 @@ users and the ZIH.
     workflows using our [datamovers](../data_transfer/datamover.md) to enable the work with larger
     datasets that might be stored on Barnard’s new capacity filesystem `/data/walrus`.
 
-## Romeo - AMD Rome CPUs
+## Romeo
+
+The cluster **Romeo** is a general purpose cluster by NEC based on AMD Rome CPUs.
 
 - 192 nodes, each with
     - 2 x AMD EPYC CPU 7702 (64 cores) @ 2.0 GHz, Multithreading available
@@ -117,7 +125,10 @@ users and the ZIH.
     2024 for good (no data access afterwards!). The new work filesystem available on Romeo will be
     `/horse`. Please [migrate your workding data to `/horse`](migration_to_barnard.md#data-migration-to-new-filesystems).
 
-## Julia - Large SMP System HPE Superdome Flex
+## Julia
+
+The cluster **Julia** is a large SMP (shared memory parallel) system by HPE based on Superdome Flex
+architecture.
 
 - 1 node, with
     - 32 x Intel(R) Xeon(R) Platinum 8276M CPU @ 2.20 GHz (28 cores)
@@ -152,9 +163,10 @@ users and the ZIH.
     system will be `/horse`. Please
     [migrate your workding data to `/horse`](migration_to_barnard.md#data-migration-to-new-filesystems).
 
-## IBM Power9 Nodes for Machine Learning
+## ML
 
-For machine learning, we have IBM AC922 nodes installed with this configuration:
+The cluster **ML** by IBM is based on Power9 CPUs and provides NVIDIA V100 GPUs.
+**ML** is specifically designed for machine learning tasks.
 
 - 32 nodes, each with
     - 2 x IBM Power9 CPU (2.80 GHz, 3.10 GHz boost, 22 cores)