message: TFLM: added reference link in README (vexriscv)
diff: # VexRISC-V
  ## Maintainers
  -
  * [danielyou0230](https://github.com/danielyou0230)
  * [tal-x](https://github.com/tcal-x)
  ## Background
  -
  -The optimized kernels for
  -[VexRISC-V](https://github.com/SpinalHDL/VexRiscv)/[Litex](https://github.com/enjoy-digital/litex)
  -are used to run Tensorflow Lite Micro in Zephyr on either
  +The optimized kernels for [VexRISC-V](https://github.com/SpinalHDL/VexRiscv)/[Litex](https://github.com/enjoy-digital/litex) are used to run Tensorflow Lite Micro in Zephyr on either
  * Digilent Arty board (e.g. Arty A7)
  -* [Renode](https://github.com/renode/renode): Open source simulation framework
  - (no hardware required)
  +* [Renode](https://github.com/renode/renode): Open source simulation framework (no hardware required)
  -To run on Digilent Arty board (FPGA,) you'll also need a soft-CPU gateware for
  -the FPGA, please see
  -[Tensorflow lite demo running in Zephyr on Litex/VexRiscv SoC](https://github.com/antmicro/litex-vexriscv-tensorflow-lite-demo)
  -by Antmicro for more details.
  +To run on Digilent Arty board (FPGA,) you'll also need a soft-CPU gateware for the FPGA, please see [Tensorflow lite demo running in Zephyr on Litex/VexRiscv SoC](https://github.com/antmicro/litex-vexriscv-tensorflow-lite-demo) by Antmicro for more details.
  -## Info
  +For general utilities, please refer to `utils/` under this directory, see [README](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/micro/kernels/vexriscv/utils/README.md) for available utilities
  -To use VexRISC-V optimized kernels instead of reference kernel add
  -`TAGS=vexriscv` to the make command. The kernels that doesn't have optimization
  -for a certain micro architecture fallback to use TFLM reference kernels.
  +## Info
  +To use VexRISC-V optimized kernels instead of reference kernel add `TAGS=vexriscv` to the make command. The kernels that doesn't have optimization for a certain micro architecture fallback to use TFLM reference kernels.
  # Example
  -To compile the binary file with VexRISC-V optimizations, one can use the
  -following command
  +To compile the binary file with VexRISC-V optimizations, one can use the following command
  ```
  make -f tensorflow/lite/micro/tools/make/Makefile \
  @@ -37,3 +27,8 @@ TAGS=vexriscv \
  TARGET=zephyr_vexriscv \
  person_detection_int8_bin
  ```
  +
  +## Optimized kernels
  +The following kernels are optimized specific to VexRISCV
  +
  +* [DepthwiseConv2D](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/micro/kernels/vexriscv/doc/DepthwiseConv2D_int8.md)
  