nixos/cgit: handle list setting type

The cgitrc file allows list of values to be set for some keys as
multiple definition lines.

This allows setting multiple "css" files to include or multiple
"readme" branch and file lookup paths to be set.

nixos/modules/services/networking/cgit.nix

@@ -6,6 +6,7 @@ let
   cfgs = config.services.cgit;
 
   settingType = with types; oneOf [ bool int str ];
+  repeatedSettingType = with types; oneOf [ settingType (listOf settingType) ];
 
   genAttrs' = names: f: listToAttrs (map f names);
 
@@ -44,12 +45,20 @@ let
       toString value
   }";
 
+  # list value as multiple lines (for "readme" for example)
+  cgitrcEntry = name: value:
+    if isList value then
+      map (cgitrcLine name) value
+    else
+      [ (cgitrcLine name value) ];
+
   mkCgitrc = cfg: pkgs.writeText "cgitrc" ''
     # global settings
     ${concatStringsSep "\n" (
-        mapAttrsToList
-          cgitrcLine
+        flatten (mapAttrsToList
+          cgitrcEntry
           ({ virtual-root = cfg.nginx.location; } // cfg.settings)
+        )
       )
     }
     ${optionalString (cfg.scanPath != null) (cgitrcLine "scan-path" cfg.scanPath)}
@@ -125,7 +134,7 @@ in
 
           settings = mkOption {
             description = "cgit configuration, see cgitrc(5)";
-            type = types.attrsOf settingType;
+            type = types.attrsOf repeatedSettingType;
             default = {};
             example = literalExpression ''
               {