Draw attention to transport later in remote cluster documentation

elastic#43858

docs/reference/modules/remote-clusters.asciidoc

@@ -63,7 +63,9 @@ to satisfy the two above requirements.
 You can configure remote clusters globally by using
 <<cluster-update-settings,cluster settings>>, which you can update dynamically.
 Alternatively, you can configure them locally on individual nodes by using the
- `elasticsearch.yml` file.
+ `elasticsearch.yml` file. Note that the connection between the clusters uses
+the transport connection string (not the http connection) which is configured
+via the <<modules-transport,transport layer>>.
 
 If you specify the settings in `elasticsearch.yml` files, only the nodes with
 those settings can connect to the remote cluster. In other words, functionality
@@ -75,20 +77,22 @@ nodes. For example:
 cluster:
     remote:
         cluster_one: <1>
-            seeds: 127.0.0.1:9300
-            transport.ping_schedule: 30s <2>
+            seeds: 127.0.0.1:9300 <2>
+            transport.ping_schedule: 30s <3>
         cluster_two: 
             seeds: 127.0.0.1:9301
-            transport.compress: true <3>
-            skip_unavailable: true <4>
+            transport.compress: true <4>
+            skip_unavailable: true <5>
 
 --------------------------------
 <1> `cluster_one` and `cluster_two` are arbitrary _cluster aliases_ representing
 the connection to each cluster. These names are subsequently used to distinguish
 between local and remote indices.
-<2> A keep-alive ping is configured for `cluster_one`.
-<3> Compression is explicitly enabled for requests to `cluster_two`.
-<4> Disconnected remote clusters are optional for `cluster_two`.
+<2> The connection string to reach the cluster via the
+<<modules-transport,transport layer>>.
+<3> A keep-alive ping is configured for `cluster_one`.
+<4> Compression is explicitly enabled for requests to `cluster_two`.
+<5> Disconnected remote clusters are optional for `cluster_two`.
 
 For more information about the optional transport settings, see
 <<modules-transport>>.