Add release notes for v2.18.0 (#3125)

* Add release notes for 2.18

Signed-off-by: Chen Dai <daichen@amazon.com>

* Remove all backport labels

Signed-off-by: Chen Dai <daichen@amazon.com>

---------

Signed-off-by: Chen Dai <daichen@amazon.com>

release-notes/opensearch-sql.release-notes-2.18.0.0.md

@@ -0,0 +1,20 @@
+Compatible with OpenSearch and OpenSearch Dashboards Version 2.18.0
+
+### Features
+
+* Backport #2981 to 2.x ([#3111](https://github.com/opensearch-project/sql/pull/3111))
+
+### Bug Fixes
+
+* Improve error handling for some more edge cases ([#3112](https://github.com/opensearch-project/sql/pull/3112))
+* Resolve Alias Issues in Legacy SQL with Filters ([#3109](https://github.com/opensearch-project/sql/pull/3109))
+* Bug Fixes for minor issues with SQL PIT refactor ([#3108](https://github.com/opensearch-project/sql/pull/3108))
+* Correct regular expression range ([#3107](https://github.com/opensearch-project/sql/pull/3107))
+* SQL pagination should work with the `pretty` parameter ([#3106](https://github.com/opensearch-project/sql/pull/3106))
+* Improve error handling for malformed query cursors ([#3084](https://github.com/opensearch-project/sql/pull/3084))
+* Remove scheduler index from SystemIndexDescriptor ([#3097](https://github.com/opensearch-project/sql/pull/3097))
+
+### Maintenance
+
+* bump commons-io to 2.14.0 ([#3091](https://github.com/opensearch-project/sql/pull/3091))
+* Fix tests on 2.18 ([#3113](https://github.com/opensearch-project/sql/pull/3113))