Add release notes for 2.19 (#585)

Signed-off-by: Tyler Ohlsen <ohltyler@amazon.com>

Author: ohltyler

release-notes/opensearch-flow-framework-dashboards.release-notes-2.19.0.0.md

@@ -0,0 +1,5 @@
+## Version 2.19.0.0 Release Notes
+
+The initial release of the Flow Framework OpenSearch Dashboards Plugin. Compatible with OpenSearch Dashboards 2.19.0
+
+This plugin provides a UI for building and testing AI/ML use cases. For further information, examples, and documentation, see [here](https://github.com/opensearch-project/dashboards-flow-framework/blob/2.x/documentation/tutorial.md).