Skills: add missing dependency metadata (#1995)

Co-authored-by: jackheuberger <jackheuberger@users.noreply.github.com>

skills/discord/SKILL.md

@@ -1,6 +1,7 @@
 ---
 name: discord
 description: Use when you need to control Discord from Clawdbot via the discord tool: send messages, react, post or upload stickers, upload emojis, run polls, manage threads/pins/search, create/edit/delete channels and categories, fetch permissions or member/role/channel info, or handle moderation actions in Discord DMs or channels.
+metadata: {"clawdbot":{"emoji":"🎮","requires":{"config":["channels.discord"]}}}
 ---
 
 # Discord Actions