Add CHANGES

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23584)

CHANGES.md

@@ -142,6 +142,11 @@ OpenSSL 3.3
 
    *Hugo Landau*
 
+ * Added APIs to allow querying the size and utilisation of a QUIC stream's
+   write buffer. Refer to the SSL_get_value_uint(3) manpage for details.
+
+   *Hugo Landau*
+
 OpenSSL 3.2
 -----------