Docs: Organize topics in the Qt Charts project

This commit organizes the articles, so they:
- have a reasonable tree structure
- can be navigated through the topic tree in the Qt Creator help viewer

Task-number: QTBUG-127024
Change-Id: I2cb1eb1b03a24a54fa12a843901b3e7a8c5b0de6
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/charts/doc/qtcharts.qdocconf

@@ -32,7 +32,11 @@ qhp.QtCharts.virtualFolder    = qtcharts
 qhp.QtCharts.indexTitle       = Qt Charts
 qhp.QtCharts.indexRoot        =
 
-qhp.QtCharts.subprojects = classes types examples
+qhp.QtCharts.subprojects = manual examples classes types
+
+qhp.QtCharts.subprojects.manual.title = Qt Charts
+qhp.QtCharts.subprojects.manual.indexTitle = Qt Charts module topics
+qhp.QtCharts.subprojects.manual.type = manual
 
 qhp.QtCharts.subprojects.classes.title      = C++ Classes
 qhp.QtCharts.subprojects.classes.indexTitle = Qt Charts C++ Classes
@@ -52,3 +56,6 @@ qhp.QtCharts.subprojects.examples.sortPages  = true
 navigation.landingpage = Qt Charts
 navigation.cppclassespage = Qt Charts C++ Classes
 navigation.qmltypespage = Qt Charts QML Types
+# Auto-generate navigation linking based on "Qt Charts module topics":
+navigation.toctitles = "Qt Charts module topics"
+navigation.toctitles.inclusive = false

src/charts/doc/src/qtcharts-toc.qdoc

@@ -0,0 +1,16 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
+
+/*!
+    \page qtcharts-toc.html
+    \title Qt Charts module topics
+
+    The following list has links to all the individual topics (HTML files)
+    in the Qt Charts module.
+
+    \list
+    \li \l {Qt Charts Overview}
+    \li \l {Changes to Qt Charts}{Upgrading from Qt 5}
+    \endlist
+
+*/