Update README.md

Author: nui4328

README.md

@@ -69,6 +69,7 @@ Read the [Contributing Guide](https://github.com/earlephilhower/arduino-pico/blo
 * Melopero Shake RP2040
 * METE HOCA Akana R1
 * MyMakers RP2040
+* MyMakers RP2350B
 * Neko Systems BL2040 Mini
 * Newsan Archi
 * nullbits Bit-C PRO