Append imported component head childNodes into importing DOM's head i…

…f present (closes #5)

main.js

@@ -165,6 +165,7 @@ async function applyImportsToDomElement(domElement, context) {
         childrenSlot.replaceWith(...importedElement.childNodes);
       }
 
+      domElement.head?.append(...importDom.window.document.head.childNodes);
       importedElement.replaceWith(...importDom.window.document.body.childNodes);
       await applyImportsToDomElement(importDom.window.document.body, context);
     }