Initial public release of WII5 Buoy firmware

Firmware for an autonomous wave-measurement buoy (ATmega2560-based
WII5 v2 board). Reads wave motion from a Sparton AHRS-M1/M2 IMU,
samples GPS and battery state, and reports back over Iridium SBD
satellite telemetry. Originally developed 2012-2024.

This is the first public release. Code, documentation, and field-tested
operating modes (Capture, Sleep, Position, ManualTest, SelfTest,
LowBattery) are licensed under Apache 2.0 — see LICENSE and NOTICE.

See README.md for an overview and build instructions, CONTRIBUTING.md
for how to contribute, and DEPLOYMENTS.md for the field-deployment log.

CHANGELOG

@@ -0,0 +1,30 @@
+v5.x - 2024
+* TODO
+
+v1.x
+* New BinData for sending/receiving binary data on the Iridium
+* Simplified and improved the button logic.
+* New logging level controls
+* GPS Debug and Passthrough in any mode
+* Better beep for Maths Start
+* Rugged Position Mode
+* Calculate time until next...
+
+v1.0.20
+* Battery And Temperature encouraged to read near boot timed
+* Hold/Click button cycle Improved
+* Power for Buzzer
+* Hold feedback messages for Displaying shutdown time of Maths
+* Sleep period configurable in EEPROM
+* Split non-essential loop out for Maths
+* Mode timeouts
+* Direct maths Hold command
+* Fully working Seep Mode
+
+v1.0.16
+* statusDump - automatically shown at Voltage and Weather to allow Local Server updates
+* Using @WII5,setting,mode,default,{STRING} has worked for a while, added "swap" which switches
+   to sleep if it was capture, otherwise to capture.
+* Updated Test help to remove incorrect documentation.
+* Large number of experimental changes in Maths to facilitate start/stop/reboot
+