docs(jpa): add release note for 5.6 about IQSS#7980

doc/release-notes/7980-enhanced-dsd.md

@@ -0,0 +1,10 @@
+### Default Values for Database Connections fixed
+
+Introduced in Dataverse release 5.3 a regression might have hit you:
+the announced default values for the database connection never actually worked.
+
+With the update to Payara 5.2022.3 it was possible to introduce working
+defaults. The documentation has been changed accordingly.
+
+Together with this change, you can now enable advanced connection pool
+configurations useful for debugging and monitoring. See the docs for details.