Set minimap height relative to editor when 'relative=editor' is configured

[konapun]

If the rel="editor" setting is used the minimap should take up the whole editor height rather than resizing to a window.

I'm using these settings:

codewindow.setup({
	relative = "editor",
	minimap_width = 10,
})

Old Behavior

In this image, the minimap only displays in the top window:

New Behavior

With these changes, the minimap window will be sized in relation to the editor rather than the current window:

Note that this still respects the max_minimap_height setting.

Btw, thanks for your work on this plugin. I previously used minimap.vim but am moving to this due to the nice lsp and treesitter integrations.