nixos/gollum: introduce --h1-title option

nixos/modules/services/misc/gollum.nix

@@ -50,6 +50,12 @@ in
       description = "Parse and interpret emoji tags";
     };
 
+    h1-title = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Use the first h1 as page title";
+    };
+
     branch = mkOption {
       type = types.str;
       default = "master";
@@ -102,6 +108,7 @@ in
             --ref ${cfg.branch} \
             ${optionalString cfg.mathjax "--mathjax"} \
             ${optionalString cfg.emoji "--emoji"} \
+            ${optionalString cfg.h1-title "--h1-title"} \
             ${optionalString (cfg.allowUploads != null) "--allow-uploads ${cfg.allowUploads}"} \
             ${cfg.stateDir}
         '';