docs(collection-field): clarify why listening to store (#493)

src/fields/collection-field.js

@@ -363,6 +363,8 @@ export default class CollectionField extends Field {
       // the typeof check to ensure that an empty RecordList doesn't bomb out when
       // newStore='{{store}}'?
       if (newStore && typeof newStore !== 'string') {
+        // Listen to changes to the store so that we can do things like display real time changes
+        // made by other users
         newStore.on('$change', this._handleStoreChangeFactory());
       }
 

src/stores/store.js

@@ -167,7 +167,7 @@ export default class Store extends UIComponent {
   }
 
   _now() {
-    // We use a DateField to avoid Firestore's automatic conversion of Date's to Firebase style
+    // We use a DateField to avoid Firestore's automatic conversion of Dates to Firebase style
     // timestamps.
     const date = new DateField({ now: true });
     return date.getValue();