Doc: Add Qt 6 changes file

Also, adjust section levels and add "." to the brief to
silence a QDoc warning.

Task-number: QTBUG-84051
Change-Id: I3adca1d56d931dbf4181c96ac150e6ccd79ea388
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

2 files changed, 52 insertions, 3 deletions

diff --git a/src/imageformats/doc/src/qt6-changes.qdoc b/src/imageformats/doc/src/qt6-changes.qdoc
new file mode 100644
index 0000000..c00857c
--- /dev/null
+++ b/src/imageformats/doc/src/qt6-changes.qdoc
@@ -0,0 +1,45 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \page qtimageformats-changes-qt6.html
+    \title Porting to Qt 6 - Qt Image Formats
+    \ingroup porting-guides-5-to-6
+    \brief Migrate Qt Image Formats to Qt 6.
+
+    Qt 6 is a result of the conscious effort to make the framework more
+    efficient and easy to use.
+
+    We try to maintain binary and source compatibility for all the public
+    APIs in each release. But some changes were inevitable in an effort to
+    make Qt a better framework.
+
+    In this topic we summarize those changes in Qt Image Formats, and provide guidance
+    to handle them.
+
+    \section1 ADD STUFF HERE
+*/
diff --git a/src/imageformats/doc/src/qtimageformats.qdoc b/src/imageformats/doc/src/qtimageformats.qdoc
index 48b76c8..e4d771f 100644
--- a/src/imageformats/doc/src/qtimageformats.qdoc
+++ b/src/imageformats/doc/src/qtimageformats.qdoc
@@ -28,7 +28,7 @@
 /*!
 \title Qt Image Formats
 \page qtimageformats-index.html
-\brief Qt Image Formats module provides support for extra image file formats
+\brief Qt Image Formats module provides support for extra image file formats.
 
 The core Qt Gui library by default supports reading and writing image
 files of the most common file formats: \c PNG, \c JPEG, \c BMP, \c GIF
@@ -77,7 +77,11 @@ plugins/imageformats), together with the default image format
 plugins. They may be deployed to the target system in the same way as
 other plugins, see the \l{Deploying Plugins} documentation.
 
-\section2 Licenses and Attributions
+\section1 Module Evolution
+\l{Porting to Qt 6 - Qt Image Formats} lists important changes in the module
+API and functionality that were done for the Qt 6 series of Qt.
+
+\section1 Licenses and Attributions
 
 Qt Image Formats is available under commercial licenses from \l{The Qt Company}.
 In addition, it is available under the
@@ -90,7 +94,7 @@ modules under following permissive licenses:
 
 \generatelist{groupsbymodule attributions-qtimageformats}
 
-\section2 Security considerations
+\section1 Security Considerations
 
 Since these file formats are more rarely used, the codecs may be less
 thoroughly debugged against potential security holes. As always, care