Clarify when to use the public folder

Author: gaearon

packages/react-scripts/template/README.md

@@ -22,6 +22,9 @@ You can find the most recent version of this guide [here](https://github.com/fac
 - [Post-Processing CSS](#post-processing-css)
 - [Adding Images and Fonts](#adding-images-and-fonts)
 - [Using the `public` Folder](#using-the-public-folder)
+  - [Changing the HTML](#changing-the-html)
+  - [Adding Assets Outside of the Module System](#adding-assets-outside-of-the-module-system)
+  - [When to Use the `public` Folder](#when-to-use-the-public-folder)
 - [Using Global Variables](#using-global-variables)
 - [Adding Bootstrap](#adding-bootstrap)
 - [Adding Flow](#adding-flow)
@@ -373,7 +376,18 @@ An alternative way of handling static assets is described in the next section.
 
 >Note: this feature is available with `[email protected]` and higher.
 
-Normally we encourage you to `import` assets in JavaScript files as described above. This mechanism provides a number of benefits:
+### Changing the HTML
+
+The `public` folder contains the HTML file so you can tweak it, for example, to [set the page title](#changing-the-page-title).
+The `<script>` tag with the compiled code will be added to it automatically during the build process.
+
+### Adding Assets Outside of the Module System
+
+You can also add other assets to the `public` folder.
+
+Note that we normally we encourage you to `import` assets in JavaScript files instead.
+For example, see the sections on [adding a stylesheet](#adding-a-stylesheet) and [adding images and fonts](#adding-images-and-fonts).
+This mechanism provides a number of benefits:
 
 * Scripts and stylesheets get minified and bundled together to avoid extra network requests.
 * Missing files cause compilation errors instead of 404 errors for your users.
@@ -410,7 +424,15 @@ Keep in mind the downsides of this approach:
 * Missing files will not be called at compilation time, and will cause 404 errors for your users.
 * Result filenames won’t include content hashes so you’ll need to add query arguments or rename them every time they change.
 
-However, it can be handy for referencing assets like [`manifest.webmanifest`](https://developer.mozilla.org/en-US/docs/Web/Manifest) from HTML, or including small scripts like [`pace.js`](http://github.hubspot.com/pace/docs/welcome/) outside of the bundled code.
+### When to Use the `public` Folder
+
+Normally we recommend importing [stylesheets](#adding-a-stylesheet), [images, and fonts](#adding-images-and-fonts) from JavaScript.
+The `public` folder is useful as a workaround for a number of less common cases:
+
+* You need a file with a specific name in the build output, such as [`manifest.webmanifest`](https://developer.mozilla.org/en-US/docs/Web/Manifest).
+* You have thousands of images and need to dynamically reference their paths.
+* You want to include a small script like [`pace.js`](http://github.hubspot.com/pace/docs/welcome/) outside of the bundled code.
+* Some library may be incompatible with Webpack and you have no other option but to include it as a `<script>` tag.
 
 Note that if you add a `<script>` that declares global variables, you also need to read the next section on using them.