fix: multistage alias from lower to uppercase

Pieter Eggink · maxhelias · commit 8a9b8c8e263c · 2021-12-15T19:05:53.000+01:00
diff --git a/docs/xdebug.md b/docs/xdebug.md
@@ -10,7 +10,7 @@ it's recommended to add a custom stage to the end of the `Dockerfile`.
 
 ```Dockerfile
 # Dockerfile
-FROM symfony_php as symfony_php_debug
+FROM symfony_php AS symfony_php_debug
 
 ARG XDEBUG_VERSION=3.0.4
 RUN set -eux; \
