Remove direct refs to securing specifications in Presentations section.

Co-authored-by: Orie Steele <[email protected]>

index.html

@@ -2037,12 +2037,8 @@ <h3>Presentations</h3>
           <dd>
 The <a>verifiable presentation</a> MAY include a <code>proof</code>
 <a>property</a>. If present, the value SHOULD be used to express a securing
-mechanism, such as [[?VC-DATA-INTEGRITY]], that is listed in the
-<a href="https://w3c.github.io/vc-specs-dir/#proof">Proof section</a> of the
-Verifiable Credentials Specifications Directory [[?VC-SPECS]]. A
-<a>verifiable presentation</a> MAY be secured using an <a>external proof</a> such as
-[[?VC-JWT]]. For details related to the use of this property, see Section
-<a href="#securing-verifiable-credentials"></a>.
+mechanism, such as those listed in the
+Verifiable Credentials Specifications Directory [[?VC-SPECS]].
           </dd>
         </dl>