The demo app is of somewhat niche interest and is disabled by default
but arguable that makes it more important to document it fully since
this app is harder to find the many others.
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
The logo module is currently unused but it simply sits there consuming
flash. Let's shift it to the demo app to is can consume RAM instead (but
only when we upload the demo to the watch).