added composer and wp-cli support

compose.yml

@@ -35,7 +35,9 @@ services:
       retries: 3
 
   wordpress:
-    image: wordpress:latest
+    build:
+      context: .
+      dockerfile: config/wordpress.Dockerfile
     depends_on:
       db:
         condition: service_healthy

config/wordpress.Dockerfile

@@ -0,0 +1,6 @@
+FROM composer:2 AS composer
+FROM wordpress:cli AS wpcli
+
+FROM wordpress:latest
+COPY --from=composer /usr/bin/composer /usr/local/bin/composer
+COPY --from=wpcli /usr/local/bin/wp /usr/local/bin/wp