[RFC wayland-protocols] Add contribution guidelines for desktop extensions

[Emil Velikov]

Hi Pekka,

On 22 February 2018 at 08:32, Pekka Paalanen <ppaalanen at gmail.com> wrote:

> +Once there is sufficient cross-desktop support for a proposal, the Wayland
> +maintainers can accept the extension into wayland-protocols.
> +
Might be worth defining "sufficient" in a bullet point somewhere.
Say, "more than 1 of the mentioned projects", or "50%+1", "2/3", etc

HTH
Emil