docs: add security warning, correct default output path

aio/content/guide/deployment.md

@@ -19,12 +19,12 @@ Both `ng build` and `ng serve` clear the output folder before they build the pro
 
 <div class="alert is-helpful">
 
-The output folder is  `dist/` by default.
+The output folder is  `dist/project-name/` by default.
 To output to a different folder, change the `outputPath` in `angular.json`.
 
 </div>
 
-Serving the contents of your output folder from a local web server can give you a better idea of how your application will behave when it is deployed to a remote server.
+As you near the end of the development process, serving the contents of your output folder from a local web server can give you a better idea of how your application will behave when it is deployed to a remote server.
 You will need two terminals to get the live-reload experience.
 
 * On the first terminal, run the [`ng build` command](cli/build) in *watch* mode to compile the application to the `dist` folder.
@@ -43,6 +43,12 @@ You will need two terminals to get the live-reload experience.
 
    The server will automatically reload your browser when new files are output.
 
+<div class="alert is-critical">
+
+This method is for development and testing only, and is not a supported or secure way of deploying an application.
+
+</div>
+
 ### Basic deployment to a remote server
 
 For the simplest deployment, create a production build and copy the output directory to a web server.