Add orderflow archive endpoint (#16)

Author: bakhtin

testdata/get-configuration.json

@@ -15,7 +15,8 @@
         "local_listen_addr": "0.0.0.0:443",
         "public_listen_addr": "0.0.0.0:5544",
         "cert_hosts": "1.2.3.4,localhost,127.0.0.1",
-        "builder_confighub_endpoint": "http://127.0.0.1:7937"
+        "builder_confighub_endpoint": "http://127.0.0.1:7937",
+        "orderflow_archive_endpoint": "https://orderflow-archive.flashbots.net"
     },
     "rbuilder": {
         "__version": "v0.1.0-26-g18875a4",