Update README.md

Author: rafamizes

README.md

@@ -30,7 +30,7 @@ Rultor.com](https://www.rultor.com/b/dartoos-dev/json_cache)](https://www.rultor
 
 **Json Cache** is an object-oriented package to cache user data locally in json.
 It can also be thought of as a layer on top of Flutter's local storage packages
-like [sharable_preferences](https://pub.dev/packages/shared_preferences)that
+like [sharable_preferences](https://pub.dev/packages/shared_preferences) that
 unifies them as an elegant caching API.