Update README.md

Author: beserge

README.md

@@ -337,6 +337,7 @@ User can add a STM32 based board following this [wiki](https://github.com/stm32d
 | :green_heart: | STM32H750IB<br>STM32H750II | Generic Board | *2.0.0* |  |
 | :green_heart: | STM32H750IB | [Daisy](https://www.electro-smith.com/daisy/daisy) | *1.9.0* |  |
 | :yellow_heart: | STM32H750IB | [Daisy Patch SM](https://www.electro-smith.com/daisy/patch-sm) | *2.2.0* |  |
+| :yellow_heart: | STM32H750IB | [Daisy Petal SM](https://www.electro-smith.com/daisy/petal-125b-sm) | *2.2.0* |  |
 | :green_heart: | STM32H750VB | Generic Board | *2.0.0* |  |
 | :yellow_heart: | STM32H750VB | [WeAct MiniSTM32H750VBT6](https://github.com/WeActTC/MiniSTM32H7xx) | **2.2.0** | [More info](https://github.com/stm32duino/Arduino_Core_STM32/pull/1552) |
 | :green_heart: | STM32H753VI | Generic Board | *2.0.0* |  |