Doc: Add doc footer and sidebar TOC

These are required for publishing the manual at doc.qt.io.

Because this doc is more a collection of articles than a
traditional guide, list the topics in this guide in the
TOC in alphabetic order.

Change-Id: I2f604ee19f81dcaaccf4601440f178b41b77ec9a
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

doc/qtcreatordev/config/style/qt5-sidebar.html

@@ -0,0 +1,16 @@
+<div class="sectionlist normallist">
+    <div class="heading">
+        <a name="reference"></a>
+        <h2 id="reference">Extending Qt Creator Manual</h2>
+    </div>
+    <div class="indexboxcont indexboxbar">
+        <ul>
+            <li><a href="creating-plugins.html"></a>Creating Plugins</li>
+            <li><a href="qtcreator-dev-wizards.html"></a>Creating Wizards in Code</li>
+            <li><a href="external-tool-spec.html"></a>External Tool Specification Files</li>
+            <li><a href="qtcreator-api.html"></a>Qt Creator API Reference</li>
+            <li><a href="coding-style.html">Qt Creator Coding Rules</a></li>
+            <li><a href="qtcreator-ui-text.html"></a>User Interface Text Guidelines</li>
+            <li><a href="qtcreator-documentation.html">Writing Documentation</a></li>
+        </ul>
+    </div>

doc/qtcreatordev/qtcreator-dev-online.qdocconf

@@ -2,3 +2,20 @@
 include(config/qtcreator-developer.qdocconf)
 include($QT_INSTALL_DOCS/global/qt-html-templates-online.qdocconf)
 
+HTML.footer = \
+    "   </div>\n" \
+    "   <p class=\"copy-notice\">\n" \
+    "   <acronym title=\"Copyright\">&copy;</acronym> $QTCREATOR_COPYRIGHT_YEAR The Qt Company Ltd.\n" \
+    "   Documentation contributions included herein are the copyrights of\n" \
+    "   their respective owners. " \
+    "   The documentation provided herein is licensed under the terms of the" \
+    "   <a href=\"http://www.gnu.org/licenses/fdl.html\">GNU Free Documentation" \
+    "   License version 1.3</a> as published by the Free Software Foundation. " \
+    "   Qt and respective logos are trademarks of The Qt Company Ltd " \
+    "   in Finland and/or other countries worldwide. All other trademarks are property\n" \
+    "   of their respective owners. </p>\n"
+
+include($QT_INSTALL_DOCS/global/qt-html-templates-online.qdocconf)
+
+# Add an .html file with sidebar content, used in the online style
+HTML.stylesheets               += config/style/qt5-sidebar.html