Remove dashes from docker folders

[lfpino]

This repo has two folderers that start with "docker-" but having dashes in the names is sometimes problematic. We should use Camelcase instead.

[Yannic]

camelCase is problematic as well because case-insensitive filesystems. Let's make it snake_case.

Also, I can't think of a case where dashes are problematic tbh.

[lfpino]

You're right, underscore xD, the dashes were problematic for the package name in Java IIRC.

I created this as a very simple good first issue :-)