fix(docs/examples): cockpitEnabled default value confusion

[petermetz]

There's a problem with the supply chain example app where some changes to the
API server broke it, but the breakage could not be consistently reproduced nor
could we figure out what was the root cause.

There is a suspicion that it is due to the out of bounds yarn install process
that is executed from the ./examples/supply-chain-app/ directory (a yarn install)
but there's no proof for this just yet.

If the latter turns out to be the root cause then to fix this bug the fix would
be likely to abandon the directory structure where we have a separate
./examples/supply-chain-app/ that installs the ...-backend package and
instead the documentation should instruct the readers to run the supply chain
backend package's entrypoint directly after a monorepo install so that the
dependencies are in-bound instead of out-of-bound (e.g. the local changes
are applied instead of the npm published packages being pulled down).

See the bottom comments on this PR:
#1623

Specifically:
#1623 (comment)
and
#1623 (comment)