Add changeset documentation

Author: github-abcde

Diff for: .changeset/use_default_value_for_ref_property.md

@@ -0,0 +1,9 @@
+---
+default: patch
+---
+
+# Use default value for ref property
+
+#1202 by @github-abcde
+
+Use defined default value for referenced properties of a model instead of always defaulting to `UNSET` in the generated code.