Lucky dev isn't shown in lucky -h

[colinkey]

When running lucky -h, it would be nice to get some information about the lucky dev command. Currently a list of available tasks is printed out. Since lucky is used for both tasks and running the dev process, getting information about the dev process as well as the available tasks would be helpful.

[matthewmcgarvey]

Problem line is here: https://github.com/luckyframework/lucky_cli/blob/45f35290dae282610ea6aa5012b31861c792a03e/src/lucky.cr#L28-L29

We also can't call lucky dev -h at the moment