fixed image urls

Author: s-m-e

README.md

@@ -7,13 +7,13 @@ 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 configuration](https://github.com/qgist/workbench/blob/master/docs/workbench_01_config.png?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 1 in QGIS](https://github.com/qgist/workbench/blob/master/docs/workbench_01_qgis.png?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 configuration](https://github.com/qgist/workbench/blob/master/docs/workbench_02_config.png?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")
+![Example workbench 2 in QGIS](https://github.com/qgist/workbench/blob/master/docs/workbench_02_qgis.png?raw=true "Example workbench 1 in QGIS")
 
 ## Branches