Release 1.8.5 - PDM library and Serial1/2.flush fix

• Fix SerialUART flush (#215)
• Add PDM library for Arduino Nano RP2040 Connect (#213)

Release 1.8.4 - Arduino Nano RP204 Connect preliminary support

• Initial Arduino Nano RP2040 Connect support (#212)

Release 1.8.3 - Serial read timeout fix

• Obey timeout value on SerialUART.read/.peek (#211)

Release 1.8.2 - Upgrade Pico-SDK, bugfix Tone() and Servo()

• Update to PICO-SDK version 1.2.0 (#207)
• Clear PIO FIFOs when updating Tone and Servos (#206)
• Clean up Arduino.h header, remove duplicates (#205)

Release 1.8.1 - Minor bugfix, SparkFun ProMicro RP2040

• Set GPIO digital output on digitalWrite (#203)
• Add PIOASM online tool link, thanks @jake653! (#197)
• Add new boards to package.json
• Add SparkFun ProMicro RP2040 (#196)
• Add back Featherwing CI test (#195)

Release 1.8.0 - GCC 10.3 and OpenOCD binaries for non Linux x86_64

• Upgrade to GCC 10.3. Fix OpenOCD packaging (#194)

Release 1.7.1 - Add Adafruit Macropad board

• Add a new board - the Adafruit Macropad w/RP2040 (#191)

Release 1.7.0 - Update tone generator, panic on illegal pin selection

• Allow continuous tone frequency changes (#186)
• Add tone music example (#185)
• Use optimal bundled library names (#183)
• PANIC on attempting an invalid setXXX pin (#182)

Release 1.6.2 - Fix broken 1.6.1 packaging

• Re-add pico-sdk/extra submodules to release ZIP (#181)

Release 1.6.1 - Automated release process

• Add TinyUSB include to all libs (#180)
• Create README describing release publish process (#179)
• CI to update JSON when releases are published (#178)
• Use CI to build draft releases on a tag push (#177)
• Check in Arduino API directory to avoid symlink (#176)