Add changelog entry

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

CHANGELOG.md

@@ -4,6 +4,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ## [Unreleased]
 ### ⚠️ Breaking Changes ⚠️
 - Moved `OpenSearch.Client` request classes into their respective namespaces to match those in `OpenSearch.Net` ([#200](https://github.com/opensearch-project/opensearch-net/pull/200), [#202](https://github.com/opensearch-project/opensearch-net/pull/202), [#203](https://github.com/opensearch-project/opensearch-net/pull/203), [#205](https://github.com/opensearch-project/opensearch-net/pull/205), [#206](https://github.com/opensearch-project/opensearch-net/pull/206), [#207](https://github.com/opensearch-project/opensearch-net/pull/207), [#208](https://github.com/opensearch-project/opensearch-net/pull/208), [#209](https://github.com/opensearch-project/opensearch-net/pull/209))
+- Removed support for the `net461` target ([#256](https://github.com/opensearch-project/opensearch-net/pull/256))
 
 ### Added
 - Added support for approximate k-NN search queries and k-NN vector index properties ([#215](https://github.com/opensearch-project/opensearch-net/pull/215))
@@ -70,4 +71,4 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Bumps `Microsoft.NETFramework.ReferenceAssemblies` from 1.0.0-preview.2 to 1.0.3
 
 [Unreleased]: https://github.com/opensearch-project/opensearch-net/compare/1.3.0...HEAD
-[1.3.0]: https://github.com/opensearch-project/opensearch-net/compare/1.2.0...1.3.0
+[1.3.0]: https://github.com/opensearch-project/opensearch-net/compare/1.2.0...1.3.0