Update concepts.yml (#2565)

Corrects a typo which alters the navigation on https://svc-cat.io/docs/concepts/

Author: buzzedword

docsite/_data/concepts.yml

@@ -7,6 +7,6 @@ toc:
   path: /docs/concepts/#introduction
 - title: Overview
   path: /docs/concepts/#overview
-- title: Serivce Resources
+- title: Service Resources
   path: /docs/concepts/#service-resources