Add Tutorial Link to Smart Contract Section (#753)

* add new .pages

* add new routes

* add test index

* test index

* remove the second option

Author: 0xlukem

develop/smart-contracts/.pages

@@ -11,3 +11,4 @@ nav:
   - 'JSON-RPC APIs': json-rpc-apis.md
   - precompiles
   - 'FAQs': faqs.md
+  - 'Tutorials': '/tutorials/smart-contracts/'