fix(doc): update typo on documentation [skip ci]

README.md

@@ -594,10 +594,10 @@ List of requirements before using this variant for publishing your container ima
 ```yaml
 include:
   - project: 'to-be-continuous/docker'
-    ref: "feature/gcp_af_login"
+    ref: "5.2.0"
     file: '/templates/gitlab-ci-docker.yml'
   - project: 'to-be-continuous/docker'
-    ref: "feature/gcp_af_login"
+    ref: "5.2.0"
     file: '/templates/gitlab-ci-docker-gcp.yml'
 
 variables: