Add comments on commits (not only in PR), I would love to have this feature 😃

Reference: #124, #124 (comment)

Thanks to gitea's team and contributors ❤️

Update: there were some attempts but they failed to make attachment management right. Pay more attention to:

• Gitea binds the attachments to repo issue/comment/release. If no binding, then the attachment will be deleted. For example: DeleteOrphanedAttachments
• checkStorage(&checkStorageOptions{Attachments: true}) deletes the attachments which don't exist in the table