Post code review changes.

Author: jmotow

libraries/dl-streamer/samples/gstreamer/README.md

@@ -26,7 +26,7 @@ Samples separated into several categories
     * [Draw Face Attributes C++ Sample](./cpp/draw_face_attributes/README.md) - constructs pipeline and sets "C" callback to access frame metadata and visualize inference results
 3. Python samples
     * [Draw Face Attributes Python Sample](./python/draw_face_attributes/README.md) - constructs pipeline and sets Python callback to access frame metadata and visualize inference results
-    * [Open Close Valve Sample](./python/open_close_valve/README.md) - constructs pipeline with two sinks. On of them has valve element, which is managed based object detection result and opened/closed by callback.
+    * [Open Close Valve Sample](./python/open_close_valve/README.md) - constructs pipeline with two sinks. On of them has valve element, which is managed based object detection result and opened/closed by callback. You can learn more about the valve element and its properties in the [GStreamer documentation](https://gstreamer.freedesktop.org/documentation/coreelements/valve.html?gi-language=python).
 4. Benchmark
     * [Benchmark Sample](./benchmark/README.md) - measures overall performance of single-channel or multi-channel video analytics pipelines