Added additional configuration flags to user-guide.md

Author: githubuser0xFFFF

demo/MainWindow.cpp

@@ -564,8 +564,6 @@ CMainWindow::CMainWindow(QWidget *parent) :
 	// CDockManager::setConfigFlag(CDockManager::HideSingleCentralWidgetTitleBar, true);
 
 	// Now create the dock manager and its content
-	CDockManager::setConfigFlag(CDockManager::DragPreviewIsDynamic, true);
-	CDockManager::setConfigFlag(CDockManager::DragPreviewShowsContentPixmap, false);
 	d->DockManager = new CDockManager(this);
 
 	// uncomment the following line to have the old style where the dock

doc/cfg_flag_DragPreviewHasWindowFrame_true.png

@@ -13,6 +13,8 @@
   - [`RetainTabSizeWhenCloseButtonHidden`](#retaintabsizewhenclosebuttonhidden)
   - [`OpaqueUndocking`](#opaqueundocking)
   - [`DragPreviewIsDynamic`](#dragpreviewisdynamic)
+  - [`DragPreviewShowsContentPixmap`](#dragpreviewshowscontentpixmap)
+  - [`DragPreviewHasWindowFrame`](#dragpreviewhaswindowframe)
 
 ## Configuration Flags
 
@@ -172,4 +174,25 @@ CDockManager::setConfigFlag(CDockManager::DragPreviewShowsContentPixmap, false);
 CDockManager::setConfigFlag(CDockManager::DragPreviewHasWindowFrame, false);
 ```
 
-![DragPreviewIsDynamic true](dynamic_drag_preview.gif)
+![DragPreviewIsDynamic true](dynamic_drag_preview.gif)
+
+### `DragPreviewShowsContentPixmap`
+
+If non-opaque undocking is enabled, the created drag preview window shows a 
+copy of the content of the dock widget / dock are that is dragged, if this
+flag is enabled (default).
+
+![DragPreviewShowsContentPixmap true](cfg_flag_DragPreviewShowsContentPixmap_true.png)
+
+If this flag is disabled, the drag preview is only a transparent `QRubberBand`
+like window without any content.
+
+![DragPreviewShowsContentPixmap true](cfg_flag_DragPreviewShowsContentPixmap_false.png)
+
+### `DragPreviewHasWindowFrame`
+
+If non-opaque undocking is enabled, then this flag configures if the drag 
+preview is frameless (default) or looks like a real window. If it is enabled,
+then the drag preview is a transparent window with a system window frame.
+
+![DragPreviewHasWindowFrame true](cfg_flag_DragPreviewHasWindowFrame_true.png)