Fix playground sample option

- change `nativeContextMenu` to `contextmenu`

test/playground.generated/interacting-with-the-editor-listening-to-mouse-events.html

@@ -60,7 +60,7 @@ var editor = monaco.editor.create(document.getElementById("container"), {
 	value: jsCode,
 	language: "javascript",
 	glyphMargin: true,
-	nativeContextMenu: false
+	contextmenu: false
 });
 
 var decorations = editor.deltaDecorations([], [

website/playground/new-samples/interacting-with-the-editor/listening-to-mouse-events/sample.js

@@ -14,7 +14,7 @@ var editor = monaco.editor.create(document.getElementById("container"), {
 	value: jsCode,
 	language: "javascript",
 	glyphMargin: true,
-	nativeContextMenu: false
+	contextmenu: false
 });
 
 var decorations = editor.deltaDecorations([], [