Merge pull request #91 from vcstuff/awoie/fix-cnf

fix: made cnf required for holder binding

draft-terbu-sd-jwt-vc.md

@@ -235,7 +235,7 @@ accepted before validating. See [@!RFC7519] for more information.
 Verifiable Credential is no longer valid. See [@!RFC7519] for more
 information.
 * `cnf`
-    * RECOMMENDED when Cryptographic Holder Binding is to be supported. Contains the confirmation method as defined in [@!RFC7800]. It SHOULD contain a JWK as defined in Section 3.2 of [@!RFC7800] and in this case, the `kid` (Key ID) member MUST be present in the JWK.  For Cryptographic Holder Binding, the Holder Binding JWT in the Combined Format for Presentation MUST be signed by the key identified in this claim.
+    * REQUIRED when Cryptographic Holder Binding is to be supported. Contains the confirmation method as defined in [@!RFC7800]. It SHOULD contain a JWK as defined in Section 3.2 of [@!RFC7800] and in this case, the `kid` (Key ID) member MUST be present in the JWK.  For Cryptographic Holder Binding, the Holder Binding JWT in the Combined Format for Presentation MUST be signed by the key identified in this claim.
 * `type`
     * REQUIRED. The type of the Verifiable Credential, e.g.,
 `IdentityCredential`, as defined in (#type-claim).