Add v2.3.0 release notes (#2318) (#2333)

Signed-off-by: Louis Chu <clingzhi@amazon.com>

* Add v2.3.0 release notes

(cherry picked from commit a19a741)

Co-authored-by: Louis Chu <lingzhichu.clz@gmail.com>

release-notes/opensearch-dashboards.release-notes-2.3.0.md

@@ -0,0 +1,31 @@
+## Version 2.3.0 Release Notes
+
+### 📈 Features/Enhancements
+
+- [D&D] Add new states in metadata slice ([#2193](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2193))
+- [D&D] Add visualization type switcher for Wizard ([#2217](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2217))
+- [D&D] Save index pattern using proper saved object structure ([#2218](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2218))
+- [D&D] Persist index field on agg type change if possible ([#2227](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2227))
+- [D&D] Add count field to field picker ([#2231](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2231))
+- [D&D] Add Bar line and Area charts to Wizard ([#2266](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2266))
+
+### 🐛 Bug Fixes
+
+- Fix maps wms zoom limitation ([#1915](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/1915))
+- [Visualizations] Add visConfig.title and uiState to build pipeline function (([#2192](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2192))
+- Custom healthcheck with filters ([#2232](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2232))
+- [BUG] Fix healthcheck logic to expect object and return ids ([#2277](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2277))
+
+### 🚞 Refactor
+
+- [DeAngular][visualization][vislib] Remove angular from vislib ([#2138](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2138))
+- Change timeline icon ([#2162](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2162))
+
+### 🛠 Maintenance
+
+- Increment from 2.2 to 2.3. ([#2096](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2096))
+
+### 🔩 Tests
+
+- [CI][tests] Add backwards compatibility (BWC) tests for 2.3.0 ([#2281](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2281))
+- Fix 2.x backwards compatibility (BWC) tests by restoring 1.3.2 ([#2284](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2284))