docs: small grammar mistake (#1818)

docs/guide/modules.md

@@ -2,7 +2,7 @@
 
 <div class="scrimba"><a href="https://scrimba.com/p/pnyzgAP/cqKK4psq" target="_blank" rel="noopener noreferrer">Try this lesson on Scrimba</a></div>
 
-Due to using a single state tree, all state of our application is contained inside one big object. However, as our application grows in scale, the store can get really bloated.
+Due to using a single state tree, all states of our application are contained inside one big object. However, as our application grows in scale, the store can get really bloated.
 
 To help with that, Vuex allows us to divide our store into **modules**. Each module can contain its own state, mutations, actions, getters, and even nested modules - it's fractal all the way down: