Revert "add placeholder inbox page"

This reverts commit 598200fa76.

lib/pages/inbox.dart

@@ -1,22 +0,0 @@
-import 'package:flutter/material.dart';
-import 'package:flutter_hooks/flutter_hooks.dart';
-
-class InboxPage extends HookWidget {
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: [
-            Text(
-              '🚧 WORK IN PROGRESS 🚧',
-              style: Theme.of(context).textTheme.headline5,
-            )
-          ],
-        ),
-      ),
-    );
-  }
-}