Update release notes for 1.2 release (#289)

Signed-off-by: Joshua Li <[email protected]>

release-notes/opensearch-sql.release-notes-1.2.0.0.md

@@ -1,8 +1,18 @@
-### **Version 1.2.0.0 Release Notes**
+### Version 1.2.0.0 Release Notes
 Compatible with OpenSearch and OpenSearch Dashboards Version 1.2.0
 
-### **Enhancement**
+### Features
 * Add new protocol for visualization response format ([#251](https://github.com/opensearch-project/sql/pull/251))
 
-### **Infrastructure**
+### Enhancements
+* Add conversion support for datetime as per https://github.com/kylepbi… ([#267](https://github.com/opensearch-project/sql/pull/267))
+* Optimized type converting in DSL filters ([#272](https://github.com/opensearch-project/sql/pull/272))
+
+### Documentation
+* Create 1.2 release notes ([#268](https://github.com/opensearch-project/sql/pull/268))
+* Update notice files ([#269](https://github.com/opensearch-project/sql/pull/269))
+* Update license header ([#282](https://github.com/opensearch-project/sql/pull/282))
+* Updated PPL user manual with relevance function limitations ([#283](https://github.com/opensearch-project/sql/pull/283))
+
+### Maintenance
 * Bumps version to 1.2 ([#254](https://github.com/opensearch-project/sql/pull/254))