docs: fix the metrics formatting (#11081)

docs/metrics/prometheus/README.md

@@ -173,12 +173,10 @@ All metrics are labeled by `bucket`, each metric is displayed per bucket. `bucke
 - *BETWEEN_128_MB_AND_512_MB*
 - *GREATER_THAN_512_MB*
 
-
 Units defintions:
 - 1 MB = 1024 KB
 - 1 KB = 1024 B
 
-
 | name                                | description                                         |
 |:------------------------------------|:----------------------------------------------------|
 | `bucket_usage_size`                 | Total size of the bucket                            |
@@ -189,7 +187,6 @@ Units defintions:
 | `bucket_replication_successful_size`| Total capacity successfully replicated              |
 | `bucket_replication_received_size`  | Total capacity received as replicated objects       |
 
-
 ### Cache specific metrics
 
 MinIO Gateway instances enabled with Disk-Caching expose caching related metrics.
@@ -202,6 +199,8 @@ MinIO Gateway instances enabled with Disk-Caching expose caching related metrics
 | `cache_data_served`  | Total number of bytes served from cache           |
 
 #### Per disk cache metrics
+| name                   | description                                                                      |
+|:-----------------------|:---------------------------------------------------------------------------------|
 | `cache_usage_size`     | Total cache usage in bytes                                                       |
 | `cache_total_capacity` | Total size of cache disk                                                         |
 | `cache_usage_percent`  | Total percentage cache usage                                                     |