feat: Elements as children

dom/src/main/scala/top/davidon/sfs/dom/Element.scala

@@ -6,5 +6,5 @@ import top.davidon.sfs.dom.tags.Tag
 class Element[+Ref <: org.scalajs.dom.Element](
     val tag: Tag[Ref],
     val mods: Iterable[Modifier[?, ?]],
-    val value: Value[?, String]
+    val children: Seq[Element[?] | Value[?, String]]
 ) {}

dom/src/main/scala/top/davidon/sfs/dom/tags/Tag.scala

@@ -10,8 +10,8 @@ trait Tag[+Ref <: dom.Element] {
   def apply(
       modifiers: Modifier[?, ?]*
   )(
-      values: Value[?, String]*
+      values: Element[?] | Value[?, String]*
   ): Element[Ref] = {
-    Element[Ref](this, modifiers, Value.join(values))
+    Element[Ref](this, modifiers, values.toSeq)
   }
 }