add donotdescend default field

Author: Arlen22

packages/jsx-lit/src/JSXElement.tsx

@@ -37,6 +37,7 @@ export class JSXElement extends ReactiveElement {
   static DO_NOT_RENDER = DO_NOT_RENDER;
 
   useLightDOM = false;
+  "webjsx-donotdescend" = false;
 
   protected events = new EventEmitter<{
     "willUpdate": [PropertyValues];