LSPPeekReference display a poup width equal current window, not usable when window width is too small

[zhyimin]

LSPPeekReference display a poup width equal current window, not usable when window width is too small, like this:

I have tried modify winwidth(0) to &column to let width of popup equal to whole window, like this.

May i create a pull request to fix it?

[Konfekt]

Of course you can. I would appreciate it; one has to agree on the minimum window width to display the popup inside it