Feature/Added Template Support to resolve #524

[vineetbambah]

Related Issue
Fixes #524

Description of Changes
Added a new option to the init command to add a template for the initialization from a list of templates. Also followed the guidelines in cli.py to help users navigate this new feature using the --help option. All except one of the supported templates in Issue #524 are included except for geojson-map which will be taken care of once Issue #733 is fixed (This is why I am not checking the last option of the checklist)

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• New example
• Test improvement

Testing
I tested by creating new preswald apps using the template option which worked completely fine as shown in the screenshot.

Also I tested for templates that do not exist yet and the error handling worked completely fine too.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have run my code against examples and ensured no errors
• Any dependent changes have been merged and published in downstream modules