Doc: Remove "Docs about UI Design" book overview

Recommending a Qt 4 book in Qt 6 documentation tells us something about
how much we maintain the list :)

The other books might still be good sources. Anyhow, the chances of a
customer looking exactly in this place to learn good books about icons are
not very high. So let's just ditch the page, and use external links instead.

Pick-to: 6.3
Change-Id: I8013a5ab9d3416fe795f4aaed647e26db79508a1
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Nicholas Bennett <nicholas.bennett@qt.io>

2 files changed, 4 insertions, 81 deletions

diff --git a/src/widgets/doc/src/external-resources.qdoc b/src/widgets/doc/src/external-resources.qdoc
index 7e60e995a1..444d538169 100644
--- a/src/widgets/doc/src/external-resources.qdoc
+++ b/src/widgets/doc/src/external-resources.qdoc
@@ -35,3 +35,7 @@
     \externalpage http://www.nvg.ntnu.no/sinclair/computers/zxspectrum/zxspectrum.htm
     \title Sinclair Spectrum
 */
+/*!
+    \externalpage https://www.pearson.com/us/higher-education/program/Gamma-Design-Patterns-Elements-of-Reusable-Object-Oriented-Software/PGM14333.html
+    \title Design Patterns
+*/
diff --git a/src/widgets/doc/src/guibooks.qdoc b/src/widgets/doc/src/guibooks.qdoc
deleted file mode 100644
index 90f6043703..0000000000
--- a/src/widgets/doc/src/guibooks.qdoc
+++ /dev/null
@@ -1,81 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 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 guibooks.html
-    \title Books about GUI Design
-    \ingroup best-practices
-    \brief Some recommended books about GUI design.
-
-    This is not a comprehensive list -- there are many other books worth
-    buying. Here we mention just a few user interface books that don't
-    gather dust on our shelves.
-
-    \b{\l{http://www.amazon.com/gp/product/0132354160/ref=ase_trolltech/}{C++
-    GUI Programming with Qt 4, Second Edition}}
-    by Jasmin Blanchette and Mark
-    Summerfield, ISBN 0-13-235416-0. This is the official Qt book written
-    by two veteran Qt Developers. The first edition, which is based on Qt 4.1, is
-    \l{http://www.qtrac.eu/C++-GUI-Programming-with-Qt-4-1st-ed.zip}{available for free online}.
-    The second edition, based on Qt 4.3, is
-    \l{http://www.informit.com/store/product.aspx?isbn=0132354160}{available for purchase as an eBook}.
-    The book predates QML and only covers widget based user interfaces.
-
-    \b{\l{http://www.amazon.com/exec/obidos/ASIN/0385267746/trolltech/t}{The Design of Everyday Things}}
-    by Donald Norman, ISBN 0-38526774-6, is one of the classics of human
-    interface design. Norman shows how badly something as simple as a
-    kitchen stove can be designed, and everyone should read it who will
-    design a dialog box, write an error message, or design just about
-    anything else humans are supposed to use.
-
-    \target Design Patterns
-    \b{\l{http://www.amazon.com/exec/obidos/ASIN/0201633612/103-8144203-3273444}
-    {Design Patterns - Elements of Reusable Object-Oriented Software}}
-    by Gamma, Helm, Johnson, and Vlissides, ISBN 0-201-63361-2, provides
-    more information on the Model-View-Controller (MVC) paradigm, explaining
-    MVC and its sub-patterns in detail.
-
-    \b{\l{http://www.amazon.com/exec/obidos/ASIN/0201622165/trolltech/t}{Macintosh
-    Human Interface Guidelines}}, Second Edition, ISBN
-    0-201-62216-5, is worth buying for the \e {don't}s alone. Even
-    if you are not writing software for \macos, avoiding most of what it
-    advises against will produce more easily comprehensible software.
-    Doing what it tells you to do may also help.
-
-    \b{\l{http://www.amazon.com/New-Windows-Interface-Microsoft-Press/dp/1556156790/}{The
-    Microsoft Windows User Experience}}, ISBN 1-55615-679-0,
-    is Microsoft's look and feel bible. Indispensable for everyone who
-    has customers that worship Microsoft, and it's quite good, too.
-
-    \b{\l{http://www.amazon.com/exec/obidos/ASIN/047159900X/trolltech/t}{The Icon Book}}
-    by William Horton, ISBN 0-471-59900-X, is perhaps the only thorough
-    coverage of icons and icon use in software. In order for icons to be
-    successful, people must be able to do four things with them: decode,
-    recognize, find and activate them. This book explains these goals
-    from scratch and how to reach them, both with single icons and icon
-    families. Some 500 examples are scattered throughout the text.
-*/