[cli] Add a big warning to stop people from modifying the global cli

react-native-cli/index.js

@@ -1,9 +1,38 @@
 #!/usr/bin/env node
 
 /**
- * Copyright 2004-present Facebook. All Rights Reserved.
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
  */
 
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// /!\ DO NOT MODIFY THIS FILE /!\
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// react-native-cli is installed globally on people's computers. This means
+// that it is extremely difficult to have them upgrade the version and
+// because there's only one global version installed, it is very prone to
+// breaking changes.
+//
+// The only job of react-native-cli is to init the repository and then
+// forward all the commands to the local version of react-native.
+//
+// If you need to add a new command, please add it to local-cli/.
+//
+// The only reason to modify this file is to add more warnings and
+// troubleshooting information for the `react-native init` command.
+//
+// Do not make breaking changes! We absolutely don't want to have to
+// tell people to update their global version of react-native-cli.
+//
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// /!\ DO NOT MODIFY THIS FILE /!\
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 'use strict';
 
 var fs = require('fs');