Add buymeacoffee

Finally, in need of some real coffee ;=))

Author: khoih-prog

README.md

@@ -6,6 +6,9 @@
 [![contributions welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat)](#Contributing)
 [![GitHub issues](https://img.shields.io/github/issues/khoih-prog/RP2040_Slow_PWM.svg)](http://github.com/khoih-prog/RP2040_Slow_PWM/issues)
 
+<a href="https://www.buymeacoffee.com/khoihprog6" target="_blank"><img src="https://cdn.buymeacoffee.com/buttons/v2/default-yellow.png" alt="Buy Me A Coffee" style="height: 60px !important;width: 217px !important;" ></a>
+
+
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@@ -137,7 +140,7 @@ The catch is **your function is now part of an ISR (Interrupt Service Routine),
 ## Prerequisites
 
  1. [`Arduino IDE 1.8.19+` for Arduino](https://github.com/arduino/Arduino). [![GitHub release](https://img.shields.io/github/release/arduino/Arduino.svg)](https://github.com/arduino/Arduino/releases/latest)
- 2. [**Earle Philhower's arduino-pico core v1.9.15+**](https://github.com/earlephilhower/arduino-pico) for RP2040-based boards such as **RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040**, etc. [![GitHub release](https://img.shields.io/github/release/earlephilhower/arduino-pico.svg)](https://github.com/earlephilhower/arduino-pico/releases/latest)
+ 2. [**Earle Philhower's arduino-pico core v1.10.0+**](https://github.com/earlephilhower/arduino-pico) for RP2040-based boards such as **RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040**, etc. [![GitHub release](https://img.shields.io/github/release/earlephilhower/arduino-pico.svg)](https://github.com/earlephilhower/arduino-pico/releases/latest)
 
  3. To use with certain example
    - [`SimpleTimer library`](https://github.com/jfturcot/SimpleTimer) to use with some examples.