Implement "Tab" autocompletion

[sbernauer]

Have a look at https://docs.rs/clap_complete/3.2.2/clap_complete/index.html especially https://github.com/clap-rs/clap/blob/master/clap_complete/examples/completion-derive.rs

[sbernauer]

Basic auto-completion was merged in #54
In case dynamic auto-completion will be needed later on a dedicated Issue should be opened