Preview window option : max-char:80 and min-char:10 option ?

Hello @junegunn ,

I have a small improvement suggestion with the library, I don't know what you think of it.

I have some cases where for the preview window, using percentages is a bit annoying because all depends on what size of window the fzf window is in.

For example, if I run the following :

fzf --preview 'cat' --preview-window 'right:50%:nohidden'

It is a bit bothering that when the terminal is taking the fullscreen, that the preview-window always takes 50% of the width.
In that case, I would prefer to have a larger filtering view.

I think this could be achieved by adding max-char and min-char to the preview-window.

Something in the line of this :

fzf --preview 'cat' --preview-window 'right:50%:nohidden:max-char:80:min-char:10'

This way, a user could say that they want to not have the preview be too big or too small.

What do you think ?

The issue names the preview-window option and provides an example command, but no source file or test. Start by locating preview-window option parsing and preview sizing, then determine how min-char and max-char should interact with percentages and nohidden. Done means the command supports bounded preview width without changing existing behavior.

Written by the indexing model from the issue text.