Add validation section regarding holder

index.html

@@ -4880,7 +4880,7 @@ <h4>Holder</h4>
 `Issuer`, `subject`, and `holder` are graph nodes which support multiple representations, 
 potentially making it complex to evaluate whether these roles are being filled
 by appropriate entities.  Validation is the process by which verifiers apply business rules to 
-evaluate the appropriateness of a particular use of a Verifiable Credential.
+evaluate the appropriateness of a particular use of a <a>verifiable credential</a>.
         </p>
         <ul>
           <li>