Merge pull request reduxjs#1027 from Restuta/patch-1

Becomes => become

Author: omnidan

docs/introduction/ThreePrinciples.md

@@ -6,7 +6,7 @@ Redux can be described in three fundamental principles:
 
 **The [state](../Glossary.md#state) of your whole application is stored in an object tree within a single [store](../Glossary.md#store).**
 
-This makes it easy to create universal apps, as the state from your server can be serialized and hydrated into the client with no extra coding effort. A single state tree also makes it easier to debug or introspect an application; it also enables you to persist your app’s state in development, for a faster development cycle. Some functionality which has been traditionally difficult to implement - Undo/Redo, for example - can suddenly becomes trivial to implement, if all of your state is stored in a single tree.
+This makes it easy to create universal apps, as the state from your server can be serialized and hydrated into the client with no extra coding effort. A single state tree also makes it easier to debug or introspect an application; it also enables you to persist your app’s state in development, for a faster development cycle. Some functionality which has been traditionally difficult to implement - Undo/Redo, for example - can suddenly become trivial to implement, if all of your state is stored in a single tree.
 
 ```js
 console.log(store.getState())