docs: more about webpack

Author: joelgallant

docs/guide/webpack/README.md

@@ -55,16 +55,16 @@ plugins: [
 ]
 ```
 
-This change tells webpack to add a `<script id="app-config">` tag, which contains
+This change tells webpack to add a `<script id="app-config">` tag, which can contain
 some JavaScript code that sets `window._appConfig`. The loader cooperates with this
 by reading from that global variable instead of inserting the config directly.
 
 Why go through this trouble? As stated above, [app-config-inject](./inject.md)
 uses this fact. When you're deploying your frontend application, you can add a
 short injection script that mutates the `index.html` with a new `<script id="app-config">`.
 By doing that, the web app will have different configuration, without changing
-the JavaScript bundle at all. If you really wanted to, you could even change the
-HTML by hand.
+the JavaScript bundle at all (allowing it to be cached). If you really wanted to,
+you could even change the HTML by hand.
 
 ### Loading Options
 
@@ -96,6 +96,21 @@ plugins: [
 ]
 ```
 
+The same goes for schema options. Use the `schemaLoading` property to define custom schema loading options.
+
+### Static App Config
+
+Use the `noGlobal: true` option and don't enable `headerInjection` - this will result in a statically
+analyzable config object, allowing it to be used like a constant variable (helpful for tree shaking).
+
+Note of course, that this has downsides - you can't inject configuration this way. We recommend using
+**multiple app configs** for that reason. You can get the best of both worlds, "feature flags" in one
+configuration file (for tree shaking), and more dynamic/environment configuration in another.
+
+### Multiple App Configs
+
+This section needs more written about it - you can find an example [here](https://github.com/launchcodedev/app-config/tree/master/tests/webpack-projects/two-app-config-sources).
+
 ### Validation
 
 A niche but useful way to use App Config involves using query parameters as configuration override.