v1.2.3 to fix `DutyCycle` and `New Period` display bugs

Releases v1.2.3

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

v1.2.2 to Use `float` for `DutyCycle` and `Freq`, `uint32_t` for `period`. and to optimize code by not calculation in ISR

Releases v1.2.2

1. Use float for DutyCycle and Freq, uint32_t for period.
2. Optimize code by not calculation in ISR

v1.2.1 to permit DutyCycle to be optionally updated at the end current PWM period instead of immediately

Releases v1.2.1

1. 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

v1.2.0 to fix `multiple-definitions` linker error, to improve accuracy and to Optimize library code by using `reference-passing` instead of `value-passing`, to fix bug, etc.

Releases v1.2.0

1. Fix multiple-definitions linker error. Drop src_cpp and src_h directories
2. Add example multiFileProject to demo for multiple-file project
3. Improve accuracy by using double, instead of uint32_t for dutycycle, period
4. Optimize library code by using reference-passing instead of value-passing
5. Fix reattachInterrupt() bug. Check bugfix: reattachInterrupt() pass wrong frequency value to setFrequency() #19
6. Update examples accordingly

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

v1.0.0 to support ISR-based multi-channel PWM for STM32F/L/H/G/WB/MP1 boards, using stm32duino STM32 core

Initial Releases v1.0.0

1. Initial coding to support STM32F/L/H/G/WB/MP1 boards such as NUCLEO_H743ZI2, NUCLEO_L552ZE_Q, NUCLEO_F767ZI, BLUEPILL_F103CB, etc., using Arduino Core for STM32
2. The hybrid ISR-based PWM channels can generate from very low (much less than 1Hz) to highest PWM frequencies up to 1000Hz with acceptable accuracy