[FLINK-37432][release] Add release note for release 2.0

Author: reswqa

docs/content.zh/_index.md

@@ -86,7 +86,8 @@ under the License.
 For some reason Hugo will only allow linking to the 
 release notes if there is a leading '/' and file extension.
 -->
-请参阅 [Flink 1.20]({{< ref "/release-notes/flink-1.20.md" >}})，
+请参阅 [Flink 2.0]({{< ref "/release-notes/flink-2.0.md" >}})，
+[Flink 1.20]({{< ref "/release-notes/flink-1.20.md" >}})，
 [Flink 1.19]({{< ref "/release-notes/flink-1.19.md" >}})，
 [Flink 1.18]({{< ref "/release-notes/flink-1.18.md" >}})，
 [Flink 1.17]({{< ref "/release-notes/flink-1.17.md" >}})，