Adding Revision history section

#2223

index.bs

@@ -9875,6 +9875,30 @@ Harry Halpin
 for their contributions as our W3C Team Contacts.
 
 
+# Revision History # {#revision-history}
+
+This section is _non-normative_.
+
+This section contains the substantive changes that have been made to this specification over time.
+
+## Changes since Web Authentication Level 2 [[webauthn-2-20210408]]
+
+- [[#sctn-credential-backup]] 
+- [[#sctn-getClientCapabilities]]
+- [[#sctn-createCredential]]
+- [[#prf-extension]]
+- [[#sctn-compound-attestation]]
+- [[#sctn-automation-set-credential-properties]]
+- [[#sctn-timeout-recommended-range]]
+- [[#ref-for-dom-publickeycredential-tojson]]
+- [[#sctn-parseCreationOptionsFromJSON]]
+- [[#sctn-parseRequestOptionsFromJSON]]
+- [[#sctn-related-origins]]
+- [[#enum-hints]]
+- [[#sctn-signalCurrentUserDetails]]
+
+
+
 <pre class=biblio>
 {