Add Option for Simplified Layout

[a-kenji]

• the simplified layout omits the Nerdfonts characters that are not
  found in every Fontset

• add an optional config option to opt into the simplified ui
  simplified_ui: bool

• add a config flag that allows opting into the simplified ui
  zellij options --simplified-ui

• move the clean flag to the setup subcommand

Closes #313.

[matu3ba]

Now that you noticed nerdfonts as dependencies: Could you add this requirement as follow-up PR to https://github.com/zellij-org/zellij#how-do-i-install-it as optional dependency?

[a-kenji]

We always noticed them as dependencies, we just haven't had a good way of requesting a simpler layout yet. Thanks for the suggestion, that is a good idea!

[a-kenji]

@TheLostLambda
Would it make sense to let people choose the separator character?
Or is that something that shouldn't be propagated?

[alexhallam]

@a-kenji I personally did not see much value in separators. The colors/layout/highlighting in zellij seemed sufficient to me. This is a subjective opinion.

[a-kenji]

@alexhallam
Thank you for the input!

Does the current functionality work for you?

add an optional config option to opt into the simplified ui
simplified_ui: true

add a config flag that allows opting into the simplified ui
zellij options --simplified-ui

[alexhallam]

I just did a new git clone

zellij options --simplified-ui

zellij --simplified-ui

I am not sure what I am doing wrong

[a-kenji]

That is indeed a little odd.
Do you mind checking:

zellij --version

and

zellij options --help

please also try

zellij option --help

Thank you!

[alexhallam]

Just want to let you know I just downloaded the most recent version. Everything is working great. Thanks for implementing this.