Add folder creation in tuto_fpga_flow.sh to ease the use

fpga_flow/tuto_fpga_flow.sh

@@ -16,6 +16,9 @@ ff_path="${pwd_path}/../vpr7_x2p/vpr/VerilogNetlists/ff.v"
 dir_keyword="GENERATED_DIR_KEYWORD"
 
 rm -rf ${pwd_path}/results_OpenPithon
+
+cd ${pwd_path}/arch
+mkdir generated	# create folder to save rewritten architecture
 cd ${pwd_path}/scripts
 
 # Replace keyword in config and architecture files