[amtk] Bump version, and start to write NEWS for next release

[Sébastien Wilmet <swilmet src gnome org>]

commit d58034488c840ff4cfe03deb57d63c77da0cdd22
Author: Sébastien Wilmet <sw swilmet be>
Date:   Fri Jan 1 06:10:36 2021 +0100

    Bump version, and start to write NEWS for next release

 NEWS        | 5 +++++
 README.md   | 2 +-
 meson.build | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/NEWS b/NEWS
index de47eeb..97d8a0b 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+News in 5.3.1, 2021-xx-yy (not yet released)
+-------------------------
+* Build: port to Meson, remove Autotools.
+* Translation updates.
+
 News in 5.2.0, 2020-09-10
 -------------------------
 * Translation updates.
diff --git a/README.md b/README.md
index 6b52707..702de32 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 Amtk - Actions, Menus and Toolbars Kit for GTK applications
 ===========================================================
 
-This is version 5.2.0 of Amtk.
+This is version 5.3.0 of Amtk.
 
 Amtk is the acronym for “Actions, Menus and Toolbars Kit”. It is a basic
 GtkUIManager replacement based on GAction. It is suitable for both a
diff --git a/meson.build b/meson.build
index 8cefec1..e1d895c 100644
--- a/meson.build
+++ b/meson.build
@@ -6,7 +6,7 @@
 project(
   'amtk', 'c',
   meson_version: '>= 0.53',
-  version: '5.2.0',
+  version: '5.3.0',
   default_options: ['warning_level=2']
 )