minor update on README over major updates

Author: jdlph

README.md

@@ -560,8 +560,9 @@ DTALite uses arrays rather than STL containers to store columns. These arrays ar
 23. Fix crucial bug in column generation module which will lead to wrong results if a zone has multiple nodes (v0.8.6)
 24. Fix crucial bug in setting up the capacity of each VDFPeriod instance if the input is missing from link.csv (v0.8.6)
 25. Add backwards compatibility on deprecated default agent type of p or passenger (v0.8.7a1)
-26. Fix potential issue that bin_index might not start from zero along with potential zero division issue when all zones have the same number of nodes in _synthesize_bin_index() (v0.8.7a1)
-27. Elaborate the legacy way of loading demand and zone information in tutorial (v0.8.7a1)
+26. Fix potential issue in setup_spnetwork() which requires zone id's are in ascending order (v0.8.7a1)
+27. Fix potential issue that bin_index might not start from zero along with potential zero division issue when all zones have the same number of nodes in _synthesize_bin_index() (v0.8.7a1)
+28. Enhance the tutorial with elaboration on the legacy way of loading demand and zone information and some caveats. (v0.8.7a1)
 
 Detailed update information can be found in [Releases](https://github.com/jdlph/Path4GMNS/releases).