add direction to onStepProgress callback

Author: maerzhase

README.md

@@ -134,6 +134,7 @@ The `onStepProgress` callback receives one argument, an object, with the followi
   element, // The DOM node of the step that was triggered
   data, // The data supplied to the step
   progress, // The percent of completion of the step (0 to 1)
+  direction, // 'up' or 'down'
 }
 ```
 

src/Step.js

@@ -71,6 +71,7 @@ const Step = props => {
         data,
         element: scrollProgressEntry.target,
         entry: scrollProgressEntry,
+        direction,
       });
     }
   }, [scrollProgressEntry]);