Documentation no longer accurate now that the nrf528xx have moved to openthread/ot-nrf528xx

[theRealeXa]

I am trying to have a go with Thread for the first time using a nRF52840-MDK and a dongle, but the OpenThread guide is no longer accurate as the path openthread/examples/platforms/nrf52840/platform-config.h is no longer valid. The examples for the nrf528xx platforms have moved to openthread/ot-nrf528xx and have changed structure as well. For example, the platform-config.h file mentioned in the tutorial does not contain the lines for UART anymore.