Update 0.5 release notes

docs/docs/the-marten-project/release-notes/0.5.md

@@ -73,6 +73,7 @@ article.category # => Category::BLOG
 * Query sets can now be combined using the AND and OR binary operators. This can be achieved through the use of the [&](../../models-and-databases/reference/query-set.md#-and) and [`|`](../../models-and-databases/reference/query-set.md#-or) query set methods.
 * Invalid record exceptions (instances of [`Marten::DB::Errors::InvalidRecord`](pathname:///api/dev/Marten/DB/Errors/InvalidRecord.html)) now provide more details regarding the actual errors of the associated record.
 * Creations of records from many-to-one reverse relation query sets are now scoped to the related record. See [Many-to-one relationships](../../models-and-databases/relationships.md#many-to-one-relationships) for more details.
+* A new [`#build`](../../models-and-databases/reference/query-set.md#build) method was introduced to make it possible to initialize new model instances from query sets.
 
 #### Handlers and HTTP