added documentation section for experimental features by @julenka

Author: bethalha-havok

Documentation/Contributing/ExperimentalFeatures.md

@@ -59,6 +59,13 @@ Adding a component menu:
 [AddComponentMenu("MRTK/Experimental/MyCommand")]
 ```
 
+## Documentation
+Follow these steps to add documentation for your experimental feature:
+
+1. Any documentation for an experimental feature should go in a `README.md` file in the experimental folder. For example, [`MixedRealityToolkit.SDK/Experimental/ScrollingObjectCollection/README.md`](../../Assets/MixedRealityToolkit.SDK/Experimental/ScrollingObjectCollection/README.md). 
+
+1. Under *Feature Overviews* Add a link in the *Experimental* section at [`Documentation/toc.yml`](../toc.yml).
+
 ### Minimize impact to MRTK code
 
 While your MRTK change might get your experiment to work, it could impact other people in ways you do not expect.