Add summary with all the planned releases

In order to have a high level overview of the release dates for all the
supported releases add a summary with the next planned releases.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>

content/release/_index.md

@@ -7,3 +7,13 @@ title = "Releases"
 
 This section contains the release notes and schedules for all current and previous releases of Apertis. Please refer to the [release schedule]({{< ref "releases.md" >}}) and [release flow]({{< ref "release-flow.md" >}}) for more information.
 
+Next planned releases:
+
+|Milestone | 2021.7 | 2022.3 | 2023pre | v2024dev0|
+|--- | --- | --- | --- | ---|
+|Start of Release Cycle | 2022-10-01 | 2022-10-01 | 2022-10-01 | 2022-10-01|
+|Soft Feature Freeze | 2022-10-26 | 2022-11-02 | 2022-11-09 | 2022-11-16|
+|Hard Feature Freeze / Soft Code Freeze | 2022-11-02 | 2022-11-09 | 2022-11-16 | 2022-11-23|
+|Release Candidate (RC1 )  / Hard Code Freeze | 2022-11-09 | 2022-11-16 | 2022-11-23 | 2022-11-30|
+|Release | 2022-11-24 | 2022-12-01 | 2022-12-08 | 2022-12-15|
+