addapted the doc

docs/basics.rst

@@ -126,6 +126,21 @@ If a workflow has been added without such a check, it can be checked later with:
 **NOTE:** The correctness check is recommended for all exercises in this tutorial.
 
 
+Visualize workflows
+-------------------
+
+Already added workflows can be converted into graphviz DOT format and viewed
+graphically using the tool provided in this tutorial in the **bin** folder::
+
+fws2dot -i <firework ID> [-v <controlflow | dataflow | combined>] [-f <filename>]
+
+After the dot file is produced it can be converted to PDF and the workflow graph 
+can be viewed::
+
+    dot -Tpdf -o workflow.pdf workflow.dot
+    evince workflow.pdf
+
+
 Launch fireworks
 ----------------