Update CHANGELOG.md

Author: bhvkshah

CHANGELOG.md

@@ -1,6 +1,15 @@
 Changelog
 =========
 
+v2.1.0.18 (2023-08-01)
+----------------------
+- Added Identity Center authentication support with new plugins [Bhavik Shah]
+- Increased HTTP server backlog size to 2 to account for Google Chrome's preloading causing HTTP requests to fail occasionally when logging in using BrowserSamlCredentialsProvider [PR#95](https://github.com/aws/amazon-redshift-jdbc-driver/pull/95) [
+Jimmy Do]
+- Fix error message shown when value provided for maxResultBuffer property cannot be parsed [Bhavik Shah]
+- Improvements for logging [Bhavik Shah]
+- Improvements for XML parsing [Bhavik Shah]
+  
 v2.1.0.18 (2023-08-01)
 ----------------------
 - Added feature to detect region automatically for IAM connections if not provided by user [Bhavik Shah]