Improve changelog

Author: alex-kulakov

ChangeLog/7.2.2-dev.txt

@@ -1,3 +1,5 @@
 [main] Query.CreateDelayedQuery(key, Func<IOrderedQueryable<TElement>>) applies external key instead of default computed, as it suppose to
 [main] QueryEndpoint.SingleAsync()/SingleOrDefaultAsync() get overloads that can recieve one key value as parameter without need to create array explicitly
+[main] PrefetchQuery<T> implements IAsyncEnumerable<T>, extra call for .AsAsyncEmumerable() is not needed for async enumeration
+[main] PrefetchQuery<T>.AsAsyncEmumerable() is marked as Obsolete
 [main] Support for C#14+ optimization that applies ReadOnlySpan<T>.Contains() extension instead of IEnumerable<T>.Contains() one to arrays