Add support for xx-npm to nodejs/vue2/buildpack

nodejs/vue2/buildpack

@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+NPM_BIN=yarn
+
+if [ "$(command -v xx-npm)" ]; then
+	NPM_BIN=xx-npm
+fi
+
 # Build Vue.js project with Docker Buildx Bake
 #
 # Docker Metadata Actions
@@ -25,16 +31,12 @@ fi
 
 pre_build() {
 	echo "=> Executing pre-build script"
-	# echo "- Installing https://github.com/google/zx"
 	echo
-	# npm install -g zx
 }
 
 post_build() {
 	echo "=> Executing post-build script"
-	# echo "- Uninstall https://github.com/google/zx"
 	echo
-	# npm uninstall -g zx
 }
 
 build() {
@@ -63,7 +65,7 @@ build() {
 	echo "-  DOCKER_META_VERSION=${DOCKER_META_VERSION}"
 	echo
 
-	yarn run build --mode ${BUILD_MODE} "$@"
+	$NPM_BIN run build --mode ${BUILD_MODE} "$@"
 }
 
 # RUN