system repl: reader quote when passing handler to the server

docs/service-repl-workflow/integrant/integrant-system.md

@@ -72,9 +72,13 @@ HTTP server start - returns function to stop the server
     (defmethod ig/init-key ::http-server
       [_ {:keys [handler port join?]}]
       (mulog/log ::http-server-component :handler handler :port port :local-time (java.time.LocalDateTime/now))
-      (http-server/run-server handler {:port port :join? join?}))
+      (http-server/run-server #'handler {:port port :join? join?}))
     ```
 
+!!! HINT "Quote handler function to evaluate changes"
+    Use `#'` reader quote when passing the `handler` function to the server so that changes to the code called by the handler function can be updated by evaluating those changes in the REPL.
+
+
 ## Shutdown Components
 
 Define how each component should be halted (if required)