Move changes from #5534 to correct place. (#5535)

Co-authored-by: Dirk Groeneveld <dirkg@allenai.org>

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added a way to resize the vocabulary in the T5 module
 - Added an argument `reinit_modules` to `cached_transformers.get()` that allows you to re-initialize the pretrained weights of a transformer model, using layer indices or regex strings.
+- Added attribute `_should_validate_this_epoch` to `GradientDescentTrainer` that controls whether validation is run at the end of each epoch.
+- Added `ShouldValidateCallback` that can be used to configure the frequency of validation during training.
 - Added a `MaxPoolingSpanExtractor`. This `SpanExtractor` represents each span by a component wise max-pooling-operation.
 
 ### Fixed
@@ -38,8 +40,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added support to push models directly to the [Hugging Face Hub](https://huggingface.co/) with the command `allennlp push-to-hf`.
 - More default tests for the `TextualEntailmentSuite`.
-- Added attribute `_should_validate_this_epoch` to `GradientDescentTrainer` that controls whether validation is run at the end of each epoch.
-- Added `ShouldValidateCallback` that can be used to configure the frequency of validation during training.
 
 ### Changed