Update README.md

Author: mixonic

README.md

@@ -2,27 +2,98 @@
 
 Migrates ember-cli projects to the newly proposed module format.
 
-See [emberjs/rfcs#143](https://github.com/emberjs/rfcs/pull/143) for details.
+This migrator does not leave an application in a bootable state. See "Usage"
+for instructions on how to manually update a migrated app to a bootable
+setup.
 
-## Examples
+See [emberjs/rfcs#143](https://github.com/emberjs/rfcs/pull/143) for details
+on the design of this app layout.
+
+### Examples
+
+These are examples of the migrator output on various apps:
 
 * [Ghost admin client](https://github.com/rwjblue/--ghost-modules-sample/tree/grouped-collections/src)
 * [Travis client](https://github.com/rwjblue/--travis-modules-sample/tree/modules/src)
-* [`ember new my-app`](https://github.com/rwjblue/--new-app-blueprint/tree/modules/src)
+* [Migration of `ember new my-app`](https://github.com/rwjblue/--new-app-blueprint/tree/modules/src)
 
 ### Usage
 
+To run the migrator on your app:
+
 ```sh
-npm install -g ember-module-migrator
+npm install -g ember-module-migrator jscodeshift
 cd your/project/path
 ember-module-migrator
 ```
 
-### Important Notes
+After running the migrator itself, you will need to update several files
+to boot an application. The best path forward is to run the
+[ember-module-unification-blueprint](https://github.com/emberjs/ember-module-unification-blueprint)
+on the converted app:
+
+```sh
+# This command will run the blueprint. Important things to note in the
+# package.json and bower.json are these package changes:
+#
+# npm i ember-resolver@^4.2.3 ember-cli@github:ember-cli/ember-cli --save-dev
+# npm uninstall ember-source --save
+# bower install --save components/ember#canary
+#
+ember init -b ember-module-unification-blueprint
+```
+
+### Running module unification with fallback to classic app layout
+
+If an application cannot be converted all at once, or if your application is
+dependent upon addons that use `app/` to add files, you may want to use
+a setup that falls back to `app/` after checking `src` and honors the `app/`
+directory for some files like initializers.
 
-Running this migrator on your application will migrate to the new structure being proposed, however at this time that structure is not fully bootable from ember-cli.  The goal right now, is for the tool to help guide us in the best module layout and for folks to be able to get a feel for what their projects will look like when things are ready to go.
+To do this use a fallback resolver in `src/resolver.js`:
+
+```js
+import ClassicResolver from 'ember-resolver';
+import Resolver from 'ember-resolver/resolvers/glimmer-wrapper';
+import buildResolverConfig from 'ember-resolver/ember-config';
+import config from '../config/environment';
+
+export default Resolver.extend({
+  config: buildResolverConfig(config.modulePrefix),
+  init(options) {
+    this._super(options);
+    this._fallback = ClassicResolver.create(Object.assign({
+      namespace: { modulePrefix: config.modulePrefix }
+    }, options));
+  },
+  resolve(name, referrer) {
+    let result = this._super(name, referrer);
+    if (!result) {
+      result = this._fallback.resolve(name);
+    }
+    return result;
+  }
+});
+```
+
+And in `src/main.js` be sure to load initializers in the `app/` directory
+(possibly added by an addon) via:
+
+```js
+/*
+ * This line should be added by the blueprint
+ */
+loadInitializers(App, config.modulePrefix+'/src/init');
+
+/*
+ * This line should be added to support `app/` directories
+ */
+loadInitializers(App, config.modulePrefix);
+```
+
+### Important Notes
 
 Known caveats:
 
-* Migrates only "classic" structured ember-cli apps at this point. We are actively working on pods support.
-* Leaves the migrated app in a non-bootable state. This is because changes are needed to ember-cli to allow the application to boot, but those changes haven't started yet.
+* Migrates only "classic" structured ember-cli apps at this point. We are
+  actively working on pods support.