Different embedded workshops unclear

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In http://localhost:3001/nrf52-troubleshoot-rust-analyzer.html we talk about these workshops, but they aren't clearly defined in the training overview

The open folder should be the nrf52-code/radio-app folder for the Radio workshop, the nrf52-code/hal-app folder for the HAL workshop, or the nrf52-code/usb-app folder for the USB workshop.