Add Service Instances Configuration text.

index.html

@@ -668,6 +668,18 @@ <h4>OAuth 2.0</h4>
       </section>
 
     </section>
+    <section>
+      <h3>Service Instances</h3>
+      <p>
+Service configuration MAY be determined by administrators on per instance basis.
+Instance configuration MAY include, but is not limited to, credential format, key options, credential status mechanisms or credential templates.
+Administrators SHOULD configure service instances such that `options` included in client requests cannot result in incorrect action or problematic responses by the service.
+      </p>
+      <p>
+A coordinator instance MAY have access to multiple service instances in order to support different use cases.
+Runtime discovery of service instance configuration is not supported by the VC API as it is expected that services are known to coordinator at the time of coordinator deployment.
+      </p>
+    </section>
     <section>
       <h3>Options</h3>
       <p>