Debugbar: Add backticks to clearly indicate code

Author: janpio

src/Outputs/Debugbar.php

@@ -15,7 +15,7 @@ public function output(Collection $detectedQueries, Response $response)
         $collector = new MessagesCollector('N+1 Queries');
 
         foreach ($detectedQueries as $detectedQuery) {
-            $collector->addMessage(sprintf('Model: %s => Relation: %s - You should add with(%s) to eager-load this relation.',
+            $collector->addMessage(sprintf('Model: %s => Relation: %s - You should add `with(%s)` to eager-load this relation.',
                 $detectedQuery['model'],
                 $detectedQuery['relation'],
                 $detectedQuery['relation']