[#2405] Make the Credential store documentation include a working example

Author: ryanemerson

documentation/asciidoc/topics/proc_securing_custom_configuration.adoc

@@ -35,7 +35,7 @@ include::yaml/credential_store.yaml[]
 
 . Apply the changes.
 . Open your {brandname} Server configuration for editing.
-. Add a `credential-reference` to your configuration.
+. Add a `credential-reference` to your configuration where required.
 .. Specify the `credentials` as the name of the `store`.
 .. Specify the `alias` attribute as one of the keys defined in your credential secret.
 +

documentation/asciidoc/topics/xml/alias_credentials_config.xml

@@ -1,4 +1,9 @@
-<credential-store>
-    <credential-reference store="credentials"  alias="postgres_cred"/>
-</credential-store>
-
+<data-source name="postgres" jndi-name="jdbc/postgres">
+    <connection-factory driver="org.postgresql.Driver"
+                        username="dbuser"
+                        url="${org.infinispan.server.test.postgres.jdbcUrl}">
+        <!-- Credential 'postgres_cred' defined in the 'user-secret' Secret is used here -->
+        <credential-reference store="credentials" alias="postgres_cred"/>
+    </connection-factory>
+    <connection-pool />
+</data-source>