[iot-pmc] github issues and contribution guidelines

[Julien Vermillard <jvermillard@xxxxxxxxx>]

Hi,

Following the last call questions about GH issues:
If you have a CONTRIBUTING.md in your repo, when someone try to open an issue or a pull-request a nice info box will point the submitter to your contribution guidelines.

It could be a nice way to ask submitters to add the correct labels to issues :)

Example:

--
Julien Vermillard