add readme

Makefile

@@ -5,4 +5,7 @@ start-backend:
 	npx start-server
 
 start:
-	make start-backend & make start-frontend
+	make start-backend & make start-frontend
+
+deploy:
+	git push heroku main

README.md

@@ -0,0 +1,22 @@
+# Example React App
+
+## Install
+
+```bash
+make install
+```
+
+## Run
+
+```sh
+$ make start
+# open http://localhost:3000
+```
+
+##
+[![Hexlet Ltd. logo](https://raw.githubusercontent.com/Hexlet/assets/master/images/hexlet_logo128.png)](https://hexlet.io/pages/about?utm_source=github&utm_medium=link&utm_campaign=react-app-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/pages/about?utm_source=github&utm_medium=link&utm_campaign=react-app-example).
+##
+
+See most active contributors on [hexlet-friends](https://friends.hexlet.io/).