Update 0.6 release notes

docs/docs/the-marten-project/release-notes/0.6.md

@@ -25,6 +25,7 @@ _Under development._
 * A new [`slugify`](../../models-and-databases/reference/fields.md#slugify) option was added to [`slug`](../../models-and-databases/reference/fields.md#slug) model fields in order to make it possible to automatically generate a slug value from another local model field.
 * Query pages (instances of [`Marten::DB::Query::Page`](pathname:///api/dev/Marten/DB/Query/Page.html)) now expose a [`#pages_count`](pathname:///api/dev/Marten/DB/Query/Page.html#pages_count-instance-method) method that allows to get the total number of pages.
 * Related objects are now automatically loaded when accessing backward relations (such as backward many-to-one relations or backward one-to-one relations).
+* The ability to retrieve specific records by using raw SQL predicates was introduced. See [Fetching single records with raw SQL predicates](../../models-and-databases/raw-sql.md#fetching-single-records-with-raw-sql-predicates) to learn more about this new capability.
 
 #### Handlers and HTTP