Add change log

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/ChangeLog.d/tls13-misc.txt b/ChangeLog.d/tls13-misc.txt
new file mode 100644
index 0000000..497ed38
--- /dev/null
+++ b/ChangeLog.d/tls13-misc.txt
@@ -0,0 +1,9 @@
+Features
+   * Mbed TLS supports TLS 1.3 key establishment via pre-shared keys,
+     pre-shared keys provisioned externally or via the ticket mechanism
+     (session resumption).
+     The MBEDTLS_SSL_SESSION_TICKETS configuration option controls the support
+     for the ticket mechanism.
+     MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_xxx_ENABLED configuration options
+     have been introduced to control the support for the three possible
+     TLS 1.3 key exchange modes.