feat: template mapping

application/source/dom/customelement.mjs

@@ -946,6 +946,11 @@ function initShadowRoot() {
         return this;
     }
 
+    const mapping = this.getOption("templateMapping", {});
+    if (isObject(mapping)) {
+        html = new Formatter(mapping).format(html);
+    }
+
     this.shadowRoot.innerHTML = html;
     return this;
 }