Update to v3.40

Author: keirf

RELEASE_NOTES

@@ -3,6 +3,12 @@
 ** Keir Fraser <[email protected]>
 ************************************
 
+** v3.40 - 27 June 2023
+ - XDF: Fix writes to side 1 of XDF disk images
+ - HFE: Better handling of long No Flux Areas
+ - QuickDisk: Reduce motor spoinup time to 1 second (previously 2 seconds)
+ - LCD: Completely blank display when backlight is off
+
 ** v3.39 - 1 March 2023
  - AT32F415: Run this MCU at 144MHz (previously 72MHz).
  - HFE: Fix HFEv3 support. Support Dungeon Master & Chaos Strikes Back.