fix: pass opts to actions.preview

[vex9z7]

It looks like an unintened mistake to not pass the opts to the callback, because without it, the preview window cannot be a horizontal split.

[stevearc]

You will also want to add a parameters table to the preview action, like the other actions that accept options. Example:

oil.nvim/lua/oil/actions.lua

Lines 22 to 43 in 1360be5

	parameters = {
	vertical = {
	type = "boolean",
	desc = "Open the buffer in a vertical split",
	},
	horizontal = {
	type = "boolean",
	desc = "Open the buffer in a horizontal split",
	},
	split = {
	type = '"aboveleft"|"belowright"|"topleft"|"botright"',
	desc = "Split modifier",
	},
	tab = {
	type = "boolean",
	desc = "Open the buffer in a new tab",
	},
	close = {
	type = "boolean",
	desc = "Close the original oil buffer once selection is made",
	},
	},

[stevearc]

Thanks for the PR!