Link attestation statement and -format in §6.1 step 10

As discussed in #561

index.bs

@@ -2098,9 +2098,9 @@ When registering a new credential, represented by a {{AuthenticatorAttestationRe
     The up-to-date list of registered WebAuthn Attestation Statement Format Identifier values
     is maintained in the in the IANA registry of the same name [[!WebAuthn-Registries]].
 
-10. Verify that |attStmt| is a correct, validly-signed attestation statement, using the attestation statement format |fmt|'s
-    verification procedure given [=authenticator data=] |authData| and the [=hash of the serialized client data=] computed in
-    step 6.
+10. Verify that |attStmt| is a correct, validly-signed [=attestation statement=], using the [=attestation statement format=]
+    |fmt|'s verification procedure given [=authenticator data=] |authData| and the [=hash of the serialized client data=] computed
+    in step 6.
 
 11. If validation is successful, obtain a list of acceptable trust anchors (attestation root certificates or [=ECDAA-Issuer
     public key=]s) for that attestation type and attestation statement format |fmt|, from a trusted source or from policy. For