Documentation link update (opensearch-project#85)

Changed documentation link in README

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

README.md

@@ -27,8 +27,8 @@
 ## Project Resources
 
 * [Project Website](https://opensearch.org/)
-* [Downloads](https://opensearch.org/downloads.html).
-* [Documentation](https://opensearch.org/docs/)
+* [Downloads](https://opensearch.org/downloads.html)
+* [Documentation](https://opensearch.org/docs/latest/clients/dot-net/)
 * Need help? Try [Forums](https://discuss.opendistrocommunity.dev/)
 * [Project Principles](https://opensearch.org/#principles)
 * [Contributing to OpenSearch](CONTRIBUTING.md)