Add `--init-templates` and `--start-theme` Flags

[SkySingh04]

This PR introduces two new flags, --init-templates and --start-theme, to the Marmite CLI, allowing users to initialize project templates and themes more easily. The new flags add the following functionality:

• --init-templates: Creates a templates/ folder in the output directory, adding a base.html file as a starter template.
• --start-theme: Extends the --init-templates command by additionally creating a static/ folder with placeholder files (style.css, script.js) referenced by the templates.

To support these new flags, two functions were added:

• initialize_templates: Sets up the templates directory and base files.
• initialize_theme_assets: Sets up the static assets directory and initial CSS/JS files.

Both functions are currently in a new module, initializer.rs, but they contain only placeholder code for now.

Questions

Before proceeding with the complete implementation, we would like some input on how the initialize_templates and initialize_theme_assets functions should be implemented. Specifically:

1. Template Content: What content should be included in the base.html file within the templates folder? Should it be a full HTML skeleton, or just a simple comment indicating where customization can begin?
2. Static Assets: Should style.css and script.js in the static/ folder include specific starter content, or can they be empty placeholders?

Related Issue : #70

[SkySingh04]

@rochacbruno Could you please review this and answer my doubts?

[SkySingh04]

@rochacbruno Your requested changes have been made!