Prevent arrow/space from scrolling the page

This is needed to make the project page work as expected. In the future, investing in ways of making those accessility features work would be good. But for now, it is broken for everyone because it both sends events to the VM _and_ scrolls the page.

src/lib/vm-listener-hoc.jsx

@@ -82,6 +82,12 @@ const vmListenerHOC = function (WrappedComponent) {
                 key: e.key,
                 isDown: true
             });
+
+            // Prevent space/arrow key from scrolling the page.
+            if (e.keyCode === 32 || // 32=space
+                (e.keyCode >= 37 && e.keyCode <= 40)) { // 37, 38, 39, 40 are arrows
+                e.preventDefault();
+            }
         }
         handleKeyUp (e) {
             // Always capture up events,