Add healthcheck configuration examples

config/environments/staging.js.example

@@ -159,6 +159,17 @@ var config = {
         handler: 'inline'
       }
     }
+    // Settings for the health check available at /health
+    ,health: {
+      enabled: false,
+      username: 'localhost',
+      query: "SELECT 1::int as interactivity_id, '0101000020110F0000EE866678CE876D41466F35C2EC1150C1'::geometry as geom, 'Lorem ipsum dolor sit amet' as label",
+      srid: 3857,
+      geometry_field: 'geom',
+      z: 0,
+      x: 0,
+      y: 0
+    }
 };
 
 module.exports = config;