Add full example appendix

docs/guides/transforms.md

@@ -51,3 +51,11 @@ A few points are useful to keep in mind while writing transforms:
 * It is in general not advised to inject arbitrary metadata into records via a transform. If you find yourself needing to supply more metadata, consider using a `ContextProvider` instead.
 * When serializing Python values (like the benchmark parameters), be careful to choose a unique representation, otherwise you might not be able to reconstruct model and data versions from written records.
 * When designing a transform that is not invertible, consider raising a `NotImplementedError` in the `iapply()` method to prevent accidental calls to the (ill-defined) inverse.
+
+## Appendix: The full example code
+
+Here is the full example on how to use transforms for record-to-file serialization:
+
+```python
+--8<-- "examples/transforms/transforms.py"
+```