Guidance on deprecating debs for snaps

[Mark Shuttleworth]

Policy for non-core apps is that newer versions should be provided as
snaps, LTS-released versions should be maintained as debs (but not
updated to newer versions).

By non-core I mean anything that is not in the ubuntu-core snap.

By apps I mean things that would make a natural snap or (in the case of
libraries) snapcraft part.

So Marco is exactly right to ask this question now, since we need to
evolve a best practice for how to socialize that there is a newer
version of the software available as a snap.

Mark