note the FIDO2 merge in release notes

RELEASE-v0.9.md

@@ -157,12 +157,14 @@ perform the Xous firmware upgrade. This requires running manual update commands,
 - refactor wait threads in net crate - use statically allocated pool of waiters + better filtering of requests for less churn
 - defer Drop on TcpStream until all written packets have been transmitted
 - scheduler quantum is now a tuning parameter in xous definitions.rs (`BASE_QUANTA_MS`). it is now set to 10ms, down from 20ms.
-- USB device core with keyboard HID emulation demo. API still needs refinement for U2F/FIDO applications.
+- USB device core with keyboard HID emulation demo and FIDO2 HID support; fix issue #170
 - Issue #162 and #159: fix bugs with condvar support. condvar IDs are now serial, so re-allocations are not a problem, and the routine to remove old ones from the notification table now looks at the correct sender ID.
 - Add `ceil`, `floor`, and `trunc` (f32 and f64) variants to the built-ins list (this is a `std` lib update, in 1.61.0.2)
 - Add CI test automation facilities - CI infra now drives actual hardware through `expect` scripts, instead of just doing simulation checks
 - Vendor in `getrandom` so we can support a Xous API for the crate, allowing us access some of the more modern rustcrypto APIs. This is necssary for `randcore` 0.6 compatibility. `randcore` 0.5 APIs are retained by integrating them directly into the TRNG object.
 - Update AES API level to 0.8, and cipher dependency to 0.4 (on rootkeys). This was necessary to get CBC support for AES, which is needed for FIDO2. This *should* have no user-facing impact.
+- `vault` app commited as a WIP of an end user authentication management app. It aims to provide FIDO2, TOTP, and stored password DB functions.
+  - currently only has stubs for FIDO2, which is a vendor-in of Google OpenSK's FIDO2 implementation.
 
 
 ## Roadmap to 1.0