Add template to create a MR with proposed changes if a build process creates modifications

mr-proposed-changes.yml

 .mr-proposed-changes:
   stage: build
-  image: registry.lakedrops.com/docker/node:12-stretch-slim
+  image: registry.lakedrops.com/docker/node:16-stretch-slim
   rules:
     - if: $CI_PIPELINE_SOURCE == "schedule"
   after_script: