Add frontend configuration

[quite]

Allow configuring of:

• time format
• indentation of message that are wrapped on a new line

[quite]

Hey! Here goes something :) It does not alter the current look of cabal-cli. But I do strongly prefer timeformat '%H%M' and indent time myself

[cblgh]

@quite wanna leave a screenshot of what it looks like for you? :)

[quite]

My preference:

[quite]

A tad ugly passing around the config like that. And passing the frontendConfig et al through the state...

[cblgh]

@quite yeah fuck it, let's merge this. i'll take on the responsibility of rewriting things if the config gets out of hand later :~

can update the readme so that people know this option exists? maybe a small section under Headless mode about configuring timestamps, with directions to read .cabal.yml-example for more information.

[quite]

Done!

[cblgh]

💯