What

Adds a /leaderboard command that displays the all-time top helpers. It reads the hall-of-fame channel history, finds messages that mention top helpers, counts how many times each user was awarded, and shows the top 10 ranked with medals.

How

Reads the hall-of-fame channel history, filters messages containing "top helper", extracts mentioned users via getMentions(), counts wins per user and shows the top 10 in an embed.

Edge cases

• Channel not found: yes, returns "Could not find the hall of fame channel."
• No messages in channel: yes, sorted.isEmpty() catches it, then returns "No top helper data found."
• Messages exist but none contain "top helper": yes, the same sorted.isEmpty() check covers it.
• Multiple users in one message: yes, the getMentions().getUsers() loop handles multiple mentions per message.

NOTE: Channel not found and Messages exist but none contain "top helper" returns the same output "No top helper data found."