upd documentation to v0.6.0 (#9)

qdrant-landing/content/documentation/quick_start.md

@@ -32,6 +32,26 @@ All interaction with Qdrant takes place via the REST API.
 This example covers the most basic use-case - collection creation and basic vector search.
 For additional information please refer to the [API documentation](https://qdrant.github.io/qdrant/redoc/index.html).
 
+### gRPC
+
+In addition to REST API, Qdrant also supports gRPC interface.
+To enable gPRC interface, specify the following lines in the [configuration file](https://github.com/qdrant/qdrant/blob/master/config/config.yaml):
+
+```yaml
+service:
+  grpc_port: 6334
+```
+
+gRPC interface will be available on the specified port.
+The gRPC methods follow the same principles as REST. For each REST endpoint, there is a corresponding gRPC method.
+Documentation on all available gRPC methods and structures is available here - [gRPC Documentation](https://github.com/qdrant/qdrant/blob/master/docs/grpc/docs.md).
+
+The choice between gRPC and the REST API is a trade-off between convenience and speed.
+gRPC is a binary protocol and can be more challenging to debug.
+We recommend switching to it if you are already familiar with Qdrant and are trying to optimize the performance of your application.
+
+If you are applying Qdrant for the first time or working on a prototype, you might prefer to use REST.
+
 ### Create collection
 First - let's create a collection with dot-production metric.
 ```bash