Update architecture/verifier/freshness.md

Co-authored-by: Thomas Fossati <thomas.fossati@arm.com>

architecture/verifier/freshness.md

@@ -30,7 +30,7 @@ freshness.
  used) with a new session request. The client can optionally specify the
  nonce to be used for this verification session, or the size of the nonce to
  be generated by Veraison. Either way, the nonce is limited to be between 8
- and 64 bytes long (see [EAT eat_nonce
+ and 64 bytes long (see [EAT `eat_nonce`
  claim](https://www.ietf.org/archive/id/draft-ietf-rats-eat-21.html#name-eat_nonce-eat-nonce-claim)).
 2. The nonce (whether provided or generated) is associated with the created
  session, and is returned in the response to the new session request.