Docs: Adding service discovery concept page (#1886)

* Adding service discovery concept page

website/data/docs-nav-data.json

@@ -100,6 +100,10 @@
         "title": "Overview",
         "path": "concepts"
       },
+      {
+        "title": "Service Discovery",
+        "path": "concepts/service-discovery"
+      },
       {
         "title": "Security",
         "routes": [