Add change log for early data feature

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/ChangeLog.d/early-data.txt b/ChangeLog.d/early-data.txt
new file mode 100644
index 0000000..bb4eb45
--- /dev/null
+++ b/ChangeLog.d/early-data.txt
@@ -0,0 +1,4 @@
+Features
+   * Mbed TLS now supports the writing and reading of TLS 1.3 early data.
+     Early data is supported when the configuration option
+     MBEDTLS_SSL_EARLY_DATA is enabled (disabled by default).