added screenshots to readme

Author: s-m-e

README.md

@@ -5,6 +5,16 @@
 QGIST Workbench is a QGIS plugin for organizing toolbars and dockwidgets.
 It is part of a larger effort, the [QGIST project](http://www.qgist.org).
 
+## Screenshots
+
+![Example workbench 1 configuration](https://github.com/qgist/workbench/docs/workbench_01_config?raw=true "Example workbench 1 configuration")
+
+![Example workbench 1 in QGIS](https://github.com/qgist/workbench/docs/workbench_01_qgis?raw=true "Example workbench 1 in QGIS")
+
+![Example workbench 2 configuration](https://github.com/qgist/workbench/docs/workbench_02_config?raw=true "Example workbench 2 configuration")
+
+![Example workbench 2 in QGIS](https://github.com/qgist/workbench/docs/workbench_02_qgis?raw=true "Example workbench 1 in QGIS")
+
 ## Branches
 
 * `master`: More or less **stable**, contains latest **release**.