update README

update README.md

add index.php

README.md

@@ -1,11 +1,11 @@
 ## set up
 ```
-docker build -t php-74 .
-docker run -it --rm -v "$PWD":/var/www php-74 bash
+docker build -t php-fpm-82 .
+docker run -it --rm -v "$PWD":/var/www php-fpm-82 bash
 composer install
 ```
 
 execute unit test
 ```
-./vendor/bin/phpunit
+./vendor/bin/phpunit tests/
 ```

src/index.php

@@ -0,0 +1,7 @@
+<?php
+require_once 'vendor/autoload.php';
+
+use App\HelloWorld;
+
+$helloWorld = new HelloWorld();
+echo $helloWorld->say();