feat(handlers): add upsertSlashCommands() (#442)

* feat(handlers): add bulk upsert commands function

* Update mod.ts

* add jsdoc

* add ID info

* ID is optional

* Update webhook.ts

* use //@ts-ignore

* idk

src/api/handlers/mod.ts

@@ -120,6 +120,7 @@ import {
   getSlashCommands,
   getWebhook,
   upsertSlashCommand,
+  upsertSlashCommands,
 } from "./webhook.ts";
 
 export let handlers = {
@@ -241,6 +242,7 @@ export let handlers = {
   getSlashCommand,
   getSlashCommands,
   upsertSlashCommand,
+  upsertSlashCommands,
   editSlashCommand,
   deleteSlashCommand,
   executeSlashCommand,