Add missing stub for Profiler

beta/src/content/apis/react/Profiler.md

@@ -0,0 +1,11 @@
+---
+title: Profiler
+---
+
+<Wip>
+
+This section is incomplete, please see the old docs for [Profiler.](https://reactjs.org/docs/profiler.html)
+
+</Wip>
+
+<InlineToc />

beta/src/sidebarAPIs.json

@@ -83,6 +83,11 @@
               "title": "<Fragment> (<>)",
               "path": "/apis/react/Fragment"
             },
+            {
+              "title": "<Profiler>",
+              "path": "/apis/react/Profiler",
+              "wip": true
+            },
             {
               "title": "<StrictMode>",
               "path": "/apis/react/StrictMode",