[ADD] website_banner module

- Task: https://www.odoo.com/web/#id=9562&view_type=form&model=project.task
- Pad: https://pad.odoo.com/p/r.z6vfT0m2KIjzoY3f
okay, but putting validation regex in website.validate_email will make code more generic and reusable @rim-odoo .