Allow actor id to be specified in config

This is useful if the actor won't be at the root of the domain.

scripts/config_wizard.py

@@ -74,6 +74,8 @@ def main() -> None:
         dat["https"] = False
         proto = "http"
 
+    dat["id"] = f'{proto}://{dat["domain"]}'
+
     print("Note that you can put your icon/avatar in the static/ directory")
     dat["icon_url"] = prompt(
         "icon URL: ", default=f'{proto}://{dat["domain"]}/static/nopic.png'