Add missing breaking doc for azure and aws

docs/reference/migration/migrate_3_0.asciidoc

@@ -121,6 +121,21 @@ function that it supports and it's able to parse. The function object can then t
 function through the new `toFunction(QueryShardContext)` method, which returns a lucene function to be executed
 on the data node.
 
+==== Cloud AWS plugin
+
+Cloud AWS plugin has been split in two plugins:
+
+* {plugins}/discovery-ec2.html[Discovery EC2 plugin]
+* {plugins}/repository-s3.html[Repository S3 plugin]
+
+==== Cloud Azure plugin
+
+Cloud Azure plugin has been split in three plugins:
+
+* {plugins}/discovery-azure.html[Discovery Azure plugin]
+* {plugins}/repository-azure.html[Repository Azure plugin]
+* {plugins}/store-smb.html[Store SMB plugin]
+
 ==== Cloud GCE plugin
 
 Cloud GCE plugin has been renamed to {plugins}/discovery-gce.html[Discovery GCE plugin].