Update README.md

Author: wasabeef

README.md

@@ -95,8 +95,9 @@ $ fluttergen -h
 $ fluttergen -c example/pubspec.yaml
 ```
 
-### Use this package as a part of build_runner
-
+### Use this package as a part of build_runner (Not recomended)
+<details><summary>Installation</summary>
+  
 1. Add [build_runner] and [FlutterGen] to your package's pubspec.yaml file:
 
 ```
@@ -117,6 +118,8 @@ $ flutter pub get
 $ flutter packages pub run build_runner build
 ```
 
+</details>
+
 ## Configuration file
 
 [FlutterGen] generates dart files based on the key **`flutter`** and **`flutter_gen`** of [`pubspec.yaml`](https://dart.dev/tools/pub/pubspec).