v1.2.1 to fix `DutyCycle` and `New Period` display bugs and to update Packages' Patches

Releases v1.2.1

1. Fix DutyCycle bug. Check float precisison of DutyCycle only sometimes working #3
2. Fix New Period display bug. Check random dropouts #4
3. Update examples
4. Update Packages' Patches

v1.2.0 to fix `multiple-definitions` linker error, improve accuracy, DutyCycle to be optionally updated at the end current PWM period instead of immediately, etc.

Releases v1.2.0

1. Fix multiple-definitions linker error. Drop src_cpp and src_h directories
2. Improve accuracy by using float, instead of uint32_t for dutycycle. Check Change Duty Cycle #1
3. DutyCycle to be optionally updated at the end current PWM period instead of immediately. Check DutyCycle to be updated at the end current PWM period #2
4. Optimize library code by using reference-passing instead of value-passing
5. Add example multiFileProject to demo for multiple-file project
6. Fix bug
7. Update examples accordingly
8. Update Packages_Patches

v1.1.0 to add functions to modify PWM settings on-the-fly

Releases v1.1.0

1. Add functions to modify PWM settings on-the-fly
2. Add example to demo how to modify PWM settings on-the-fly

Initial Release v1.0.0 to support multi-channel slower PWM for Portenta_H7 boards, using ArduinoCore-mbed mbed_portenta core

Initial Releases v1.0.0

1. Initial coding to support Portenta_H7 boards such as Portenta_H7 Rev2 ABX00042, etc., using ArduinoCore-mbed mbed_portenta core. Max PWM frequency is limited at 1000Hz.