The contribution checklist currently covers only a very narrow subset of
possible submissions, primarily new Apertis specific code and APIs. This is no
longer a major part of what Apertis is providing and many of the requirements
do not reflect current practice.

Remove the existing checklist and provide a new one that covers points to be
covered for code, component and design submissions, breaking down when and
where responsibility lies during the development and submission process.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>