improve readme

Author: ashikov

README.md

@@ -1,5 +1,24 @@
 # hexlet-slim-example
 
+[![PHP CI](https://github.com/hexlet-components/slim-example/actions/workflows/phpci.yml/badge.svg)](https://github.com/hexlet-components/slim-example/actions/workflows/phpci.yml)
+
+Demo: https://slim-example.hexlet.app/
+
+## Requirements
+
+* PHP >=7.4
+* Composer
+
+## Usage
+
+```bash
+make setup
+make start
+```
+
+Open in browser: http://localhost:8000
+
+---
 [![Hexlet Ltd. logo](https://raw.githubusercontent.com/Hexlet/assets/master/images/hexlet_logo128.png)](https://hexlet.io?utm_source=github&utm_medium=link&utm_campaign=hexlet-slim-example)
 
 This repository is created and maintained by the team and the community of Hexlet, an educational project. [Read more about Hexlet](https://hexlet.io?utm_source=github&utm_medium=link&utm_campaign=hexlet-slim-example).