fix(tutorial): add missing semicolon in export_data function

Author: amaurigmartins

examples/tutorial3.jl

@@ -372,4 +372,4 @@ end
 
 # Export ZY matrices to ATPDraw
 output_file = fullfile("ZY_export.xml")
-export_file = export_data(:atp, line_params, f; file_name=output_file, cable_system=cable_system)
+export_file = export_data(:atp, line_params, f; file_name=output_file, cable_system=cable_system);