Add Zalando blog post to resources

Signed-off-by: Fiore Mario Vitale <mvitale@redhat.com>

Author: mfvitale

documentation/online-resources.asciidoc

@@ -210,6 +210,7 @@ CDC in Azure Database for MySQL – Flexible Server using Kafka, Debezium, and A
 * https://www.propeldata.com/blog/postgresql-cdc-to-kafka[How to stream PostgreSQL CDC to Kafka and use Propel to get an instant API] by Tyler Wells
 * https://medium.com/@alessandroalacorte/transitioning-from-batch-imports-to-cdc-with-debezium-c1caa3693697[Transitioning from Batch Imports to CDC with Debezium] by Alessandro La Corte
 * https://medium.com/@kavpreet/building-cdc-data-pipelines-on-databricks-with-debezium-kafka-0cc9593cc803["Building CDC Data Pipelines on Databricks with Debezium + Kafka"] by Kavpreet Grewal
+* https://engineering.zalando.com/posts/2025/12/contributing-to-debezium.html["Contributing to Debezium: Fixing Logical Replication at Scale"] by Conor Gallagher
 
 == Example Code