Signal trapping for easy shutdown without killing backend container

docker/backend/src/backend/runner.cr

@@ -35,6 +35,9 @@ module Backend
 
     # Run the backend
     def run : self
+      Signal::INT.trap { exit }
+      Signal::TERM.trap { exit }
+
       {% if flag?(:development) %}
         Log.warn { "Backend is running in development mode! Do not use this in production!" }
       {% end %}