Add 2.2.0.0 release notes (#484)

Signed-off-by: Junqiu Lei <junqiu@amazon.com>

release-notes/opensearch-knn.release-notes-2.2.0.0.md

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+## Version 2.2.0.0 Release Notes
+
+Compatible with OpenSearch 2.2.0
+
+### Features
+* Lucene Based k-NN search support([#486](https://github.com/opensearch-project/k-NN/pull/486))
+
+### Enhancements
+* Add KNN codec that is based on Lucene92 codec([#444](https://github.com/opensearch-project/k-NN/pull/444))
+* Remove support for innerproduct for lucene engine([#488](https://github.com/opensearch-project/k-NN/pull/488))
+* Increase max dimension to 16k for nmslib and faiss([#490](https://github.com/opensearch-project/k-NN/pull/490))
+
+### Bug Fixes
+* Reject delete model request if model is in Training([#424](https://github.com/opensearch-project/k-NN/pull/424))
+* Change call to Lucene VectorSimilarityFunction.convertToScore([#487](https://github.com/opensearch-project/k-NN/pull/487))
+
+### Infrastructure
+* Add fix to flaky test in ModelDaoTests([#463](https://github.com/opensearch-project/k-NN/pull/463))
+* Read BWC Version from GitHub workflow([#476](https://github.com/opensearch-project/k-NN/pull/476))
+* Staging for version increment automation([#442](https://github.com/opensearch-project/k-NN/pull/442))
+* Remove 1.0.0 for BWC test([#492](https://github.com/opensearch-project/k-NN/pull/492))
+
+### Maintenance
+* Bump OpenSearch version to 2.2.0([#471](https://github.com/opensearch-project/k-NN/pull/471))
+* Bump Gradle version to 7.5([#472](https://github.com/opensearch-project/k-NN/pull/472))
+* Bump default bwc version to 1.3.4([#477](https://github.com/opensearch-project/k-NN/pull/477))
+
+### Refactoring
+* Move engine and lib components into separate files([#438](https://github.com/opensearch-project/k-NN/pull/438))
+* Refactor knn type and codecs([#439](https://github.com/opensearch-project/k-NN/pull/439))
+* Move mappers to separate files([#448](https://github.com/opensearch-project/k-NN/pull/448))