tsuki/invidious: remove redundant code, add comments

hosts/tsuki/services/invidious.nix

@@ -10,6 +10,7 @@
 
     port = 19283;
 
+    # This will implicitly use unix socket
     database = {
       createLocally = true;
       passwordFile = config.sops.secrets."postgres/invidious".path;
@@ -18,13 +19,8 @@
     settings = {
       registration_enabled = false;
       host_binding = "127.0.0.1";
-
       # popular_enabled = false;
     };
   };
-
-  systemd.services.invidious = {
-    requires = [ "postgresql.service" ];
-  };
 }