Documentation: Add 4.20 release notes template and update index

Also update Month abbreviations to full month names.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I99c1a037c0fc3d0cfec6464956f4263debdfccd4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/71941
Reviewed-by: Felix Singer <felixsinger@posteo.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/Documentation/releases/coreboot-4.20-relnotes.md b/Documentation/releases/coreboot-4.20-relnotes.md
new file mode 100644
index 0000000..2065f44
--- /dev/null
+++ b/Documentation/releases/coreboot-4.20-relnotes.md
@@ -0,0 +1,67 @@
+Upcoming release - coreboot 4.20
+========================================================================
+
+The 4.20 release is planned for the 20th of April 2023.
+
+
+The 4.21 release is planned for around the 17th of July, 2023
+
+
+Update this document with changes that should be in the release notes.
+
+* Please use Markdown.
+* See the past few release notes for the general format.
+* The chip and board additions and removals will be updated right
+  before the release, so those do not need to be added.
+* Note that all changes before the release are done are marked upcoming.
+  A final version of the notes are done after the release.
+
+* This document may also be edited at the google doc copy:
+  https://docs.google.com/document/d/1_0PeRxzT7ep8dIZobzIqG4n6Xwz3kkIDPVQURX7YTmM/edit
+
+Significant or interesting changes
+----------------------------------
+
+### Add changes that need a full description here
+
+
+
+Additional coreboot changes
+---------------------------
+
+The following are changes across a number of patches, or changes worth
+noting, but not needing a full description.
+
+* Changes that only need a line or two of description go here.
+
+
+
+
+Plans to move platform support to a branch
+------------------------------------------
+
+### Intel Quark SoC & Galileo mainboard
+
+The SoC Intel Quark is unmaintained and different efforts to revive it
+have so far failed.  The only user of this SoC ever was the Galileo
+board.
+
+Thus, to reduce the maintanence overhead for the community, support for
+the following components will be removed from the master branch and will
+be maintained on the release 4.20 branch.
+
+  * Intel Quark SoC
+  * Intel Galileo mainboard
+
+
+Statistics from the 4.19 to the 4.20 release
+--------------------------------------------
+
+* To be filled in immediately before the release by the release team
+
+
+Significant Known and Open Issues
+---------------------------------
+
+* To be filled in immediately before the release by the release team
+
diff --git a/Documentation/releases/index.md b/Documentation/releases/index.md
index 4e36920..e8adbd5 100644
--- a/Documentation/releases/index.md
+++ b/Documentation/releases/index.md
@@ -3,7 +3,7 @@
 ## Upcoming release
 
 Please add to the release notes as changes are added:
-* [4.19 - Jan 2023](coreboot-4.19-relnotes.md)
+* [4.20 - April 2023](coreboot-4.20-relnotes.md)
 
 The [checklist] contains instructions to ensure that a release covers all
 important things and provides a reliable format for tarballs, branch
@@ -15,9 +15,10 @@
 
 ## Previous releases
 
-* [4.18 - Oct 2022](coreboot-4.18-relnotes.md)
+* [4.19 - January 2023](coreboot-4.19-relnotes.md)
+* [4.18 - October 2022](coreboot-4.18-relnotes.md)
 * [4.17 - May 2022](coreboot-4.17-relnotes.md)
-* [4.16 - Feb 2022](coreboot-4.16-relnotes.md)
+* [4.16 - February 2022](coreboot-4.16-relnotes.md)
 * [4.15 - November 2021](coreboot-4.15-relnotes.md)
 * [4.14 - May 2021](coreboot-4.14-relnotes.md)
 * [4.13 - November 2020](coreboot-4.13-relnotes.md)