Update shard db sections in the example config file

cfg/rippled-example.cfg

@@ -385,7 +385,7 @@
 #
 #   [ips]
 #   192.168.0.1
-#   192.168.0.1 2459 
+#   192.168.0.1 2459
 #   r.ripple.com 51235
 #
 #
@@ -458,7 +458,7 @@
 #   Configure the maximum number of transactions to have in the job queue
 #
 #   Must be a number between 100 and 1000, defaults to 250
-# 
+#
 #
 # [overlay]
 #
@@ -957,7 +957,18 @@
 #   Required keys:
 #       path                Location to store the database
 #
-#       max_size_gb         Maximum disk space the database will utilize (in gigabytes)
+#   Optional keys:
+#       max_historical_shards
+#                           The maximum number of historical shards
+#                           to store.
+#
+#   [historical_shard_paths]      Additional storage paths for the Shard Database (optional)
+#
+#   Format (without spaces):
+#       One or more lines, each expressing a full path for storing historical shards:
+#       /mnt/disk1
+#       /mnt/disk2
+#       ...
 #
 #   [sqlite]       Tuning settings for the SQLite databases (optional)
 #
@@ -1359,7 +1370,14 @@ advisory_delete=0
 # https://xrpl.org/history-sharding.html
 #[shard_db]
 #path=/var/lib/rippled/db/shards/nudb
-#max_size_gb=500
+#max_historical_shards=50
+#
+# This optional section can be configured with a list
+# of paths to use for storing historical shards. Each
+# path must correspond to a unique filesystem.
+#[historical_shard_paths]
+#/path/1
+#/path/2
 
 [database_path]
 /var/lib/rippled/db