Provide metrics on root URL

lib/kafkaex_lag_exporter_web/router.ex

@@ -0,0 +1,11 @@
+defmodule KafkaexLagExporterWeb.Router do
+  use KafkaexLagExporterWeb, :router
+
+  pipeline :api do
+    plug :accepts, ["json"]
+  end
+
+  scope "/api", KafkaexLagExporterWeb do
+    pipe_through :api
+  end
+end