README.md

? Nuvoton BSP descriptions
Current supported BSP shown in below table:

| **BSP folder** | **Board name** |
|:------------------------- |:-------------------------- |
| [numaker-iot-m487](numaker-iot-m487) | Nuvoton NuMaker-IoT-M487 |
| [numaker-pfm-m487](numaker-pfm-m487) | Nuvoton NuMaker-PFM-M487 |
| [nk-980iot](nk-980iot) | Nuvoton NK-980IOT |
| [numaker-m2354](numaker-m2354) | Nuvoton NuMaker-M2354 |
| [nk-rtu980](nk-rtu980) | Nuvoton NK-RTU980 |