import { previewwindow } from "https://deno.land/x/denops_std@v5.0.1/option/mod.ts";
Identifies the preview window. Only one window can have this option
set. It's normally not set directly, but by using one of the commands
:ptag, :pedit, etc.
(default off)
not available when compiled without the +quickfix feature
type
LocalOption<boolean>