Clarify use of mailing list
Clarify use of mailing list

- Create new mailing list section
- Add mailing list in contribution section

Signed-off-by: Kanta Vekaria <ae794cff6c0c11be1be9c869e6aaf3ec0e3cf52e@linaro.org>
Signed-off-by: Rob Herring <fbb37eacae100e13076d5c4b46f06cfa4d6fa9f8@kernel.org>

devicetree-org/devicetree-specification