support threads

flake.nix

@@ -50,6 +50,9 @@
             type = lib.types.str;
             description = "The webhook to post the messages to";
           };
+          threadId = lib.mkOption {
+            type = lib.types.str;
+          };
           users =
             lib.mkOption {
               type = lib.types.listOf lib.types.attrs;

index.js

@@ -19,6 +19,7 @@ for (let user of config.users) {
 
     await webhook.send({
       content: message,
+      threadId: config.threadId,
       username: "WaniKani Reminder",
       avatarURL: "https://pbs.twimg.com/profile_images/1213575248911552512/WP11ESTy_400x400.jpg",
       allowedMentions: {