fix up doc comments

Author: morganchen12

FirebaseDatabaseUI/FirebaseArrayDelegate.h

@@ -38,7 +38,7 @@
 - (void)array:(FirebaseArray *)array didAddObject:(id)object atIndex:(NSUInteger)index;
 
 /**
- * Delegate method which is called whenever an object is chinged in a
+ * Delegate method which is called whenever an object is changed in a
  * FirebaseArray. On a FirebaseArray synchronized to a Firebase reference, 
  * this corresponds to a @c FIRDataEventTypeChildChanged event being raised.
  * @param object The object that changed in the FirebaseArray

FirebaseDatabaseUI/FirebaseIndexArray.h

@@ -132,7 +132,7 @@ didFailLoadWithError:(NSError *)error;
 
 /**
  * Initializes a FirebaseIndexArray with an index query and a data query.
- * The array expects the keys of the children of the index query to be children
+ * The array expects the keys of the children of the index query to match exactly children
  * of the data query.
  * @param index A Firebase database query whose childrens' keys are all children 
  *   of the data query.