docs: added-flagsmith-openfeature-doc

Author: Zaimwa9

docs/docs/clients/openfeature.md

@@ -23,6 +23,7 @@ We currently offer [OpenFeature Providers](https://docs.openfeature.dev/docs/ref
 - [Java](https://github.com/open-feature/java-sdk-contrib/tree/main/providers/flagsmith)
 - [.Net](https://github.com/open-feature/dotnet-sdk-contrib/tree/main/src/OpenFeature.Contrib.Providers.Flagsmith)
 - [JavaScript/Web](https://github.com/open-feature/js-sdk-contrib/tree/main/libs/providers/flagsmith-client)
+- [JavaScript/Server](https://github.com/open-feature/js-sdk-contrib/tree/main/libs/providers/flagsmith)
 - [Python](https://github.com/Flagsmith/flagsmith-openfeature-provider-python)
 
 ### Planned Providers