This also accounts for dagger.io/dagger/core split introduced in
https://github.com/dagger/dagger/pull/1866
We should hold this merge until we are ready to cut the release,
otherwise links & some instructions will be broken until we release
v0.2.3.
Even though I would have preferred to have docs/update-version.sh in
Dagger, this is the quickest thing for now.
Related to https://github.com/dagger/dagger/issues/1854
Signed-off-by: Gerhard Lazu <gerhard@lazu.co.uk>