v1.7.0 for the new PushPull mode, to fix bug, etc.

[khoih-prog]

Releases v1.7.0

1. Add functions setPWMPushPull_Int, setPWMPushPull and setPWMPushPull_Period for the new PushPull mode. Check pwm_set_output_polarity #21
2. Add these examples to demo the new PushPull mode

• PWM_PushPull
• PWM_PushPull_DynamicDC
• PWM_PushPull_DynamicFreq

3. Fix bug of half frequency when using phaseCorrect mode
4. Improve README.md so that links can be used in other sites, such as PIO

---

This discussion was created from the release v1.7.0 for the new `PushPull` mode, to fix bug, etc..