Recycling Robot: incorrect return value in example (#2730)

Author: glennj

exercises/concept/recycling-robot/.docs/instructions.md

@@ -83,7 +83,7 @@ isElectronic(new Duck());
 // => false
 
 isElectronic(new WashingMachine());
-// => false
+// => true
 ```
 
 ### 6. Check if a value is a non empty array