added Group type

Sources/Elementary/Core/Group.swift

@@ -0,0 +1,43 @@
+/// A container that groups HTML content without introducing any additional HTML tags.
+///
+/// This type is useful when you want to return multiple sibling nodes from a single `some HTML`
+/// context without adding an extra wrapper element.
+///
+/// - Note: In Embedded mode, the HTML builder currently supports up to **6 direct child views**
+///   in a single block (because variadic generics aren't available there yet). You can exceed
+///   that limit by nesting content inside one or more `Group` blocks.
+public struct Group<Content: HTML>: HTML {
+    public typealias Tag = Never
+    public typealias Body = Never
+    public typealias Content = Content
+
+    public let content: Content
+
+    @inlinable
+    public init(@HTMLBuilder content: () -> Content) {
+        self.content = content()
+    }
+
+    @inlinable
+    public static func _render<Renderer: _HTMLRendering>(
+        _ html: consuming Self,
+        into renderer: inout Renderer,
+        with context: consuming _RenderingContext
+    ) {
+        context.assertNoAttributes(self)
+        Content._render(html.content, into: &renderer, with: context)
+    }
+
+    @inlinable
+    @_unavailableInEmbedded
+    public static func _render<Renderer: _AsyncHTMLRendering>(
+        _ html: consuming Self,
+        into renderer: inout Renderer,
+        with context: consuming _RenderingContext
+    ) async throws {
+        context.assertNoAttributes(self)
+        try await Content._render(html.content, into: &renderer, with: context)
+    }
+}
+
+extension Group: Sendable where Content: Sendable {}

Tests/ElementaryTests/TagRenderingTests.swift

@@ -33,6 +33,24 @@ final class TagRenderingTests: XCTestCase {
         )
     }
 
+    func testRendersGroup() async throws {
+        try await HTMLAssertEqual(
+            div {
+                Group {
+                    h1 {}
+                    Group {
+                        if true {
+                            p {}
+                            p {}
+                        }
+                    }
+                    h1 {}
+                }
+            },
+            "<div><h1></h1><p></p><p></p><h1></h1></div>"
+        )
+    }
+
     func testRendersOptionals() async throws {
         try await HTMLAssertEqual(
             div {