Proxy local frontend to remote backend (#1452)

* add server proxy configurations

* change address to host due to compliation warning

* adjust config sample to more accurately reflect production version

frontend/config-sample.json

@@ -14,6 +14,11 @@
     "mocks": {
       "maskAs": "tor",
       "skipStartupAlerts": true
+    },
+    "marketplace": {
+      "url": "https://beta-registry-0-3.start9labs.com/",
+      "name": "Embassy Marketplace"
     }
-  }
+  },
+  "gitHash": ""
 }