refactor ETL graph

sh/gen_doc.sh

@@ -0,0 +1,23 @@
+
+
+# Work in progress ...
+#
+# generate ETL graph from all layers 
+# start from the root :
+#   ./sh/gen_doc.sh
+#
+# outut ->  ./doc/ 
+
+
+mkdir -p ./doc/
+rm -f ./doc/*
+for f in ./layers/*
+do
+	echo "Processing : $f"
+    layer_id=$(echo "$f" | rev | cut -d"/" -f1 | rev )
+    echo "layer_id = $layer_id"
+    ./sh/gen_etl_graph.sh $layer_id
+
+done
+
+