How to build PlatformIO based project

1. Install PlatformIO Core
2. Download development platform with examples
3. Extract ZIP archive
4. Run these commands:

# Change directory to example
> cd platform-nordicnrf52/examples/mbed-ble-thermometer

# Build project
> platformio run

# Upload firmware
> platformio run --target upload

# Build specific environment
> platformio run -e nrf52_dk

# Upload firmware for the specific environment
> platformio run -e nrf52_dk --target upload

# Clean build files
> platformio run --target clean