DOCSP-9533: [Guides] typo fix (#149)

Author: steveren

source/includes/steps-fts-sample-app.yaml

@@ -121,7 +121,7 @@ content: |
           score: {
             $meta: 'searchScore'
           },
-          hightlight: {
+          highlight: {
             $meta: 'searchHighlights'
           }
         }