Update ChangeLog

Author: RKBoss6

apps/clock_info/ChangeLog

@@ -18,4 +18,5 @@
 0.17: Fix BLE icon alignment and border on some clocks
 0.18: Tweak BLE icon to add gap and ensure middle of B isn't filled
 0.19: Fix Altitude ClockInfo after BLE added
-      Tapping Altitude now updates the reading
+      Tapping Altitude now updates the reading
+0.20: Altitude ClockInfo now uses the distance units set in locale.