fix: clarify Discord onboarding hint (#1487)

Thanks @kyleok.

Co-authored-by: Ganghyun Kim <58307870+kyleok@users.noreply.github.com>

src/channels/plugins/onboarding/discord.ts

@@ -47,7 +47,7 @@ async function noteDiscordTokenHelp(prompter: WizardPrompter): Promise<void> {
       "1) Discord Developer Portal → Applications → New Application",
       "2) Bot → Add Bot → Reset Token → copy token",
       "3) OAuth2 → URL Generator → scope 'bot' → invite to your server",
-      "Tip: enable Message Content Intent if you need message text.",
+      "Tip: enable Message Content Intent if you need message text. (Bot → Privileged Gateway Intents → Message Content Intent)",
       `Docs: ${formatDocsLink("/discord", "discord")}`,
     ].join("\n"),
     "Discord bot token",