[16.0][ADD] website_blog_email_template: add new module

[marcelsavegnago]

This module extends the website blog functionality by allowing you to configure custom email templates for new blog post notifications.

Main Features

• Custom Email Templates: Configure a custom email template for each blog to personalize notifications
• Template Selection: Choose from existing mail templates or create new ones specifically for blog notifications
• Context Access: Templates have access to blog post information through context variables
• Backward Compatible: If no custom template is configured, the default template is used
• Link to Post: Templates can include direct links to the published blog post

Benefits

• Personalize email notifications for different blogs
• Create branded email templates matching your company style
• Include additional information in notifications (author, subtitle, etc.)
• Maintain consistency with your email marketing campaigns
• Better control over notification content and formatting

Dependencies

This module requires:

• website_blog: Odoo's website blog module

[WesleyOliveira98]

LGTM