[hotfix] [docs] Add Release Notes for Flink 1.6.

docs/index.md

@@ -45,6 +45,7 @@ Before putting your Flink job into production, read the [Production Readiness Ch
 
 Release notes cover important changes between Flink versions. Please carefully read these notes if you plan to upgrade your Flink setup to a later version. 
 
+* [Release notes for Flink 1.6](release-notes/flink-1.6.html).
 * [Release notes for Flink 1.5](release-notes/flink-1.5.html).
 
 ## External Resources

docs/release-notes/flink-1.6.md

@@ -0,0 +1,26 @@
+---
+title: "Release Notes - Flink 1.6"
+---
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements. See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership. The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied. See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+These release notes discuss important aspects, such as configuration, behavior, or dependencies, that changed between Flink 1.5 and Flink 1.6. Please read these notes carefully if you are planning to upgrade your Flink version to 1.6.
+
+
+{% top %}