This commit adds a feature where users can register a callback that is called when an LEDC fade completes.
Example: Added LEDC basic PWM example Closes DO-70 See merge request espressif/esp-idf!13114
Changes on the ledc_init function Review on the README, docs and example functions Added how to set freq and duty on README Fix on the ledc.rst docs in the App Example Added new example reference in the Chinese docs