feat: support windows paths in embedded templates FS

tarfs/tarfs.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"io"
 	"io/fs"
+	"os"
 	"path"
 	"sort"
 	"strings"
@@ -71,20 +72,20 @@ func (fsys FS) Open(name string) (fs.File, error) {
 	if name == "." {
 		elem = "."
 		for fname, f := range fsys {
-			i := strings.Index(fname, "/")
+			i := strings.Index(fname, string(os.PathSeparator))
 			if i < 0 {
 				list = append(list, fileInfo{fname, f})
 			} else {
 				need[fname[:i]] = true
 			}
 		}
 	} else {
-		elem = name[strings.LastIndex(name, "/")+1:]
-		prefix := name + "/"
+		elem = name[strings.LastIndex(name, string(os.PathSeparator))+1:]
+		prefix := name + string(os.PathSeparator)
 		for fname, f := range fsys {
 			if strings.HasPrefix(fname, prefix) {
 				felem := fname[len(prefix):]
-				i := strings.Index(felem, "/")
+				i := strings.Index(felem, string(os.PathSeparator))
 				if i < 0 {
 					list = append(list, fileInfo{felem, f})
 				} else {