feat: add --boilerplate option to rc-apps create command

[ShubhamS2005]

Description

This PR adds support for a --boilerplate option in the rc-apps create command.

The flag allows developers to generate commonly used Rocket.Chat app components when creating a new app.

Supported boilerplates:

• Slash Command
• API Endpoint
• Settings

Example:

rc-apps create --name MyApp --boilerplate slash-command

This will generate a starter Slash Command template inside the created app.

Changes

• Added --boilerplate flag to the create command
• Integrated existing boilerplate templates
• Added validation for supported boilerplate options
• Automatically generates corresponding template files

Testing

Tested locally by creating apps with each boilerplate option:

rc-apps create --name=TestApp --boilerplate slash-command
rc-apps create --name=TestApp --boilerplate api-endpoint
rc-apps create --name=TestApp --boilerplate settings

All templates were generated correctly and packaging works as expected.

The Below image shows the creation of starter , using the boiler code

This PR automatically closes #181