Replace unsupported wip tld by localhost (#254)

Author: duboiss

docs/build.md

@@ -28,7 +28,7 @@ For instance, use the following command to use the `master` branch of Symfony:
 
 Use the `SERVER_NAME` environment variable to define your custom server name(s).
 
-    SERVER_NAME="symfony.wip, caddy:80" docker-compose up --build
+    SERVER_NAME="symfony.localhost, caddy:80" docker-compose up --build
 
 If you use Mercure, keep `caddy:80` in the list to allow the PHP container to request the caddy service.