Documentation: Update RELEASENOTES to include v1.1.0

Signed-off-by: Rashika Kheria <rashika@amazon.com>

RELEASENOTES.md

@@ -4,9 +4,32 @@
 * Amazon Linux
 * Amazon Linux 2
 * Redhat Enterprise Linux 7.0
-* Ubuntu 16.04 LTS
+* Ubuntu 16.04, 18.04 and 20.04 LTS
 * CentOS 7
 
+# v1.1.0 release notes
+
+This release requires [Libfabric v1.11.0](https://github.com/ofiwg/libfabric/releases/tag/v1.11.0)and supports [NCCL v2.7.8](https://github.com/NVIDIA/nccl/releases/tag/v2.7.8-1)
+while maintaining backward compatibility with older NCCL versions (upto
+[NCCL v2.4.8](https://github.com/NVIDIA/nccl/releases/tag/v2.4.8-1)).
+
+It introduces the following new features and bug fixes.
+
+New Features:
+* Detect and support multi-NIC environment
+* Support GPUDirect RDMA when libfabric providers support it
+* Add `flush` API support for transfers using CUDA buffers
+
+Bug Fixes:
+* Enable `RDMAV_FORK_SAFE` environment variable
+
+Testing:
+The plugin has been tested with following libfabric providers using unit tests
+bundled in the source code:
+* tcp;ofi_rxm
+* sockets
+* efa
+
 # v1.0.1 release notes
 
 This release supports [NCCL v2.6.4](https://github.com/NVIDIA/nccl/releases/tag/v2.6.4-1)