Add OpenTelemetry interceptors (#491)

Author: AlmogBaku

README.md

@@ -68,6 +68,7 @@ _Please send a PR to add new interceptors or middleware to this list_
 - [`grpc_prometheus`⚡](https://github.com/grpc-ecosystem/go-grpc-prometheus) - Prometheus client-side and server-side monitoring middleware
 - [`otgrpc`⚡](https://github.com/grpc-ecosystem/grpc-opentracing/tree/master/go/otgrpc) - [OpenTracing](http://opentracing.io/) client-side and server-side interceptors
 - [`grpc_opentracing`](tracing/opentracing) - [OpenTracing](http://opentracing.io/) client-side and server-side interceptors with support for streaming and handler-returned tags
+- [`otelgrpc`](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation/google.golang.org/grpc/otelgrpc) - [OpenTelemetry](https://opentelemetry.io/) client-side and server-side interceptors
 
 #### Client