Cover use of dedicated project areas for patching components

We state that authors of submissions to extend existing components could be asked to submit the change upstream, however we do not cover the option of using a dedicated project area for tweaked components should changes not be of general applicability to Apertis.

Highlight that dedicated project areas may be made available for this purpose.

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