Use exec to let the container runtime send signals straight to rails (#5505)

This is recommended practice. See the docker documentation at
https://docs.docker.com/develop/develop-images/instructions/#entrypoint


for more information.

Co-authored-by: Ahmad Farhat <ahmad.af.farhat@gmail.com>

bin/start

@@ -28,4 +28,4 @@ rails assets:precompile
 rails db:create
 rails db:migrate:with_data
 
-rails s -b 0.0.0.0 -p $PORT
+exec rails s -b 0.0.0.0 -p $PORT