Bug: Windows().Tag contains only the first line

Expected behavior

Windows().Tag contains the full content of the tag.

Windows() is possibly backed by index file, as defined in acme(4). If it's not possible to expose the full content of tag, possibly indicate it in the documentation.

Unexpected behavior

It only has the first line.

Steps to reproduce the problem

wins, _ := acme.Windows()
for _, w := range wins {
	fmt.Println(w.Tag)
}

9fans.net/go/acme version

v0.0.7