Fixed Vale errors and updated formatting

Author: DHBR2

docs/guides/databases/cassandra/deploy-cassandra-multi-datacenters/index.md

@@ -496,15 +496,15 @@ seed_provider:
 - **Do not make every node a seed**
 
 
-#### Listen_address
+#### `listen_address`
 
 Set the node's private Akamai IP.
 
 ```yaml
 listen_address: 10.0.1.5
 ```
 
-#### rpc_address
+#### `rpc_address`
 
 The default value (localhost) binds RPC to the loopback interface only. For a cluster, replace it with the node’s private IP so other nodes and clients can reach it.