docs: added link to user guide (#2129)

www/docs/docusaurus.config.js

@@ -64,6 +64,11 @@ module.exports = {
           sidebarId: "tutorialSidebar",
           label: "Docs"
         },
+        {
+          type: "docSidebar",
+          sidebarId: "userGuideSidebar",
+          label: "User Guide"
+        },
         {
           type: 'dropdown',
           label: 'REST API Reference',