Update Motivation.md (reduxjs#2042)

Author: alextsg

docs/introduction/Motivation.md

@@ -1,6 +1,6 @@
 # Motivation
 
-As the requirements for JavaScript single-page applications have become increasingly complicated, **our code must manage more state than ever before**. This state can include server responses and cached data, as well as locally created data that has not yet been persisted to the server. UI state is also increasing in complexity, as we need to manage the active route, the selected tab, whether to show a spinner or not, should pagination controls be displayed, and so on.
+As the requirements for JavaScript single-page applications have become increasingly complicated, **our code must manage more state than ever before**. This state can include server responses and cached data, as well as locally created data that has not yet been persisted to the server. UI state is also increasing in complexity, as we need to manage active routes, selected tabs, spinners, pagination controls, and so on.
 
 Managing this ever-changing state is hard. If a model can update another model, then a view can update a model, which updates another model, and this, in turn, might cause another view to update. At some point, you no longer understand what happens in your app as you have **lost control over the when, why, and how of its state.** When a system is opaque and non-deterministic, it's hard to reproduce bugs or add new features.