Doc: Describe functions for inspecting web content in Features topic

Add a short description and links to the new QWebEnginePage functions
and WebEngineView QML properties.

Task-number: QTBUG-66780
Change-Id: I205d1d922caac1c82a11054055ec44924942249d
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

src/webengine/doc/src/qtwebengine-features.qdoc

@@ -82,6 +82,15 @@
     {Simple Browser} or \l{WebEngine Quick Nano Browser}{Nano Browser}) to connect
     to \c {http://localhost:[your-port]}.
 
+    The Chromium DevTools page can also be shown within the application. To set
+    this up, you can call either QWebEnginePage::setInspectedPage() to the page
+    to be inspected, which implicitly loads the DevTools into the \c this page,
+    or QWebEnginePage::setDevToolsPage() to let the \c this page be inspected.
+
+    The respective QML properties are \l{WebEngineView::devToolsView}
+    {WebEngineView.devToolsView} and \l{WebEngineView::inspectedView}
+    {WebEngineView.inspectedView}.
+
     For more information, see \l {Qt WebEngine Debugging and Profiling}.
 
     \section1 Drag and Drop