feat(discord): automate posting of selected charts to Discord

[marcgc21]

Description

Implement a system that automatically posts selected charts:

• issue activity -> to inform how many issues were created, are open or were closed.
• pull request activity weekly --> to inform how many PR were created, are open or were closed.
• best contributors of the month --> ranking of the top commit pushers
• This helps keep contributors updated with project analytics in real time or at scheduled intervals.

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🧾 Requirements

• Generate chart images
• Upload charts to a Discord channel using a bot
• Support manual trigger and scheduled posting (e.g., weekly summary and monthly summary)

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✅ Tasks

• Set up or reuse a Discord bot with access to the target channel
• Define which charts to send (e.g., top 3 most relevant for the team)
• Export chart visualizations as image files
• Send chart images with contextual messages (e.g., titles, stats summary)
• (Optional) Allow command trigger (e.g., /charts week)
• (Optional) Add cron/scheduler to send updates weekly or monthly

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📁 Example Output

Weekly Update – Top Contributors

🏆 @alice: 34 commits | @bob: 21 commits

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✅ Acceptance Criteria

• Bot sends charts to Discord without manual upload
• Messages include visual + short text context
• Scheduled and/or on-demand commands supported
• Clean, readable output in Discord

[kartikeyg0104]

Sir, assign me this issue.