Add Self-Service API to top navbar

docusaurus.config.js

@@ -73,6 +73,11 @@ module.exports = {
               type: 'doc',
               label: 'Routing-API',
               docId: 'apis/routing-api'
+            },
+            {
+              type: 'doc',
+              label: 'Self-Service API',
+              docId: 'apis/self-service-api'
             }
           ]
         },