enlarge functional simple ranging/interrupt example, to cater for multi-zone.

Dependencies:   X_NUCLEO_53L1A2

Revision:
0:e91189a84ad9
diff -r 000000000000 -r e91189a84ad9 mbed-os.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Sun Nov 08 15:49:23 2020 +0000
@@ -0,0 +1,1 @@
+https://github.com/armmbed/mbed-os/#aa70f680bb5755e8fea3f93fc6e04d9b3de235bb