Add Custom Warmup Templates to E-Warmup, allowing users to create personalized warmup emails using Plain Text or HTML. Users can assign templates to multiple connected mailboxes, manage all templates from a single dashboard, enable or disable warmup per template, and view the number of connected mailboxes using each template. The feature should also support editing and deleting templates, enabling users to warm up their inboxes using their own email copy or reusable templates.