Document experimental imports

Author: nicolasstucki

docs/docs/reference/other-new-features/experimental-defs.md

@@ -10,7 +10,10 @@ This annotation can be placed on term or type definitions.
 
 ### References to experimental definitions
 
-Experimental definitions can only be referenced in an experimental scope. Experimental scopes are defined as follows.
+- Experimental definitions can only be referenced in an experimental scope.
+- Experimental language features can be imported in an experimental scope.
+
+Experimental scopes are defined as follows.
 
 (1) The RHS of an experimental `def`, `val`, `var`, `given` or `type` is an experimental scope.