Move changes in RELEASE.md to docs section

Signed-off-by: Ahdra Merali <ahdra.merali@quantumblack.com>

RELEASE.md

@@ -10,7 +10,6 @@
 * Dropped the dependency on `toposort` in favour of the built-in `graphlib` module.
 * Improved the performance of `Pipeline` object creation and summing.
 * Improved suggestions to resume failed pipeline runs.
-* Added documentation on best practices for testing nodes and pipelines.
 
 
 ## Bug fixes and other changes
@@ -25,7 +24,8 @@
 * Methods `_is_project` and `_find_kedro_project` have been moved to `kedro.utils`. We recommend not using private methods in your code, but if you do, please update your code to use the new location.
 
 ## Documentation changes
-* Add missing description for `merge_strategy` argument in OmegaConfigLoader.
+* Added missing description for `merge_strategy` argument in OmegaConfigLoader.
+* Added documentation on best practices for testing nodes and pipelines.
 
 ## Community contributions
 Many thanks to the following Kedroids for contributing PRs to this release: