Add prettify stage to legacy script

.gitlab-ci.yml

@@ -6,6 +6,7 @@ services:
 
 ## Should contain at least these three stages for a basic CI/CD
 stages:
+  - formatting
   - build
   - test
   - release
@@ -16,6 +17,11 @@ variables:
   DOCKER_BUILDKIT: "1"
   DOCKER_TLS_CERTDIR: ""
 
+prettify:
+  stage: formatting
+  script:
+    - cd backend
+    - npm run-script prettify
 
 build:
   variables: