ZDM-593 (#148)

* added diagram of How different sets of credentials are used by the ZDM Proxy

* updated zdm-proxy-credential-usage image to new, brand-compliant one

* Changed caption to How different sets of credentials are used by the ZDM Proxy when authentication is enabled on both clusters

Author: emeliawilkinson24

docs-src/zdm-core/modules/migrate/images/zdm-proxy-credential-usage.png

@@ -112,6 +112,9 @@ This means that, if your {zdm-proxy} is configured with an Origin or Target clus
 
 |===
 
+.How different sets of credentials are used by the ZDM Proxy when authentication is enabled on both clusters
+image::zdm-proxy-credential-usage.png[ZDM proxy credentials usage, 550]
+
 === A note on the Astra Secure Connect Bundle
 If your {zdm-proxy} is configured to use Astra DB as an Origin or Target, your client application **does not need** to provide an Astra Secure Connect Bundle (SCB) when connecting to the proxy. It will, however, have to supply the Astra client ID and client secret as a username and password (respectively).