Fix presets packages references in migration guide

Fix missing react package and presets references in babel config inside migration guide

Author: afdev82

docs/switch_from_webpacker.md

@@ -130,7 +130,7 @@ You can use Babel to transpile front-end frameworks and TypeScript. This example
 
 ```sh
 # From the CLI, add babel presets
-yarn add @babel/core @babel/preset-env @babel/react @babel/preset-typescript
+yarn add @babel/core @babel/preset-env @babel/preset-react @babel/preset-typescript
 ```
 
 2. Configure Babel
@@ -139,8 +139,8 @@ yarn add @babel/core @babel/preset-env @babel/react @babel/preset-typescript
 // In package.json, add
 + "babel": {
 +   "presets": [
-+     "@babel/env",
-+     "@babel/react",
++     "@babel/preset-env",
++     "@babel/preset-react",
 +     "@babel/preset-typescript"
 +   ]
 + }