Prettify usage help

[fritschldwg]

Feature request

Description

• As a first-time-user, I want the usage help to be simple and easily understandable

Acceptance criteria

• The help output is consistent with the actual usage (file or folder is specified first)
• The help output is consistent accross parsers
• The help output is cleanly formatted

Development notes

• Docker help can serve as reference for a well structured help output

Screeenshots

[ce-bo]

@fritschldwg Let's have a short session to check the current issues here together please.