Update NN Documentation
![GitHub release (latest by date including pre-releases)](https://img.shields.io/github/v/release/ARM-software/CMSIS-NN?include_prereleases) ![GitHub](https://img.shields.io/github/license/ARM-software/CMSIS-NN)
This CMSIS component has been moved into its own realm, please find it at [ARM-software/CMSIS-NN](https://github.com/ARM-software/CMSIS-NN).
+Users of pre-TFLM quantization API's can use the [5.9.0](https://github.com/ARM-software/CMSIS_5/releases/tag/5.9.0) release of CMSIS_5 for that.
