Added intended installation instruction

I have added the intended installation instruction to the README because Packagist doesn't show the correct installation instruction.
So if people want to install it quickly with the intended installation instruction can do so.

Author: wotta

README.md

@@ -8,6 +8,14 @@ Bringing the [Symfony Var-Dump Server](https://symfony.com/doc/current/component
 
 This package will give you a dump server, that collects all your `dump` call outputs, so that it does not interfere with HTTP / API responses.
 
+## Installation
+
+You can install the package via composer:
+
+```bash
+composer require --dev beyondcode/laravel-dump-server
+```
+
 ## Documentation
 
 You can find the documentation on the [Beyond Code website](https://beyondco.de/docs/laravel-dump-server/installation).