Document `useRefreshable` hook

lib/hooks/refreshable.dart

@@ -13,6 +13,13 @@ class Refreshable<T> {
   final AsyncCallback refresh;
 }
 
+/// Similar to [useMemoFuture] but adds a `.refresh` method which
+/// allows to re-run the fetcher. Calling `.refresh` will not
+/// turn AsyncSnapshot into a loading state. Instead it will
+/// replace the ready state with the new data when available
+///
+/// `keys` will re-run the initial fetching thus yielding a
+/// loading state in the AsyncSnapshot
 Refreshable<T> useRefreshable<T>(AsyncValueGetter<T> fetcher,
     [List<Object> keys = const <dynamic>[]]) {
   final newData = useState<T>(null);

lib/widgets/infinite_scroll.dart

@@ -28,10 +28,8 @@ class InfiniteScroll<T> extends HookWidget {
   final InfiniteScrollController controller;
   final Widget prepend;
   final EdgeInsetsGeometry padding;
-  final GlobalKey<RefreshIndicatorState> _refreshIndicatorKey =
-      GlobalKey<RefreshIndicatorState>();
 
-  InfiniteScroll({
+  const InfiniteScroll({
     this.batchSize = 10,
     this.prepend = const SizedBox.shrink(),
     this.padding,
@@ -65,7 +63,6 @@ class InfiniteScroll<T> extends HookWidget {
     final page = data.value.length ~/ batchSize + 1;
 
     return RefreshIndicator(
-      key: _refreshIndicatorKey,
       onRefresh: () async {
         controller.clear();
         await HapticFeedback.mediumImpact();