Add Configuration Templates

[Carrington-dev]

Description

Create template system for generating configuration files.

Tasks

• Create template engine integration
• Add built-in templates (Django, FastAPI, Flask)
• Support custom templates
• Add template variables
• Create dotzen init --template command
• Add template validation
• Create template gallery
• Document template creation
• Add community template support

Acceptance Criteria

• Templates generate valid config
• Multiple frameworks supported
• Easy to create custom templates
• Well documented