External Disk Path

[Luis Gonzalez]

Is your feature request related to a problem? Please describe.
As a developer, I'd like to set the source path from a Laravel disk so that I can for example allocate my markdown files in an external disk like a cloud bucket or external service provider and I can add/update/delete on demand rather than making changes in the code.

Describe the solution you'd like

• The disk can be specified in the config file.
• The other parts of larecipe would remind the same.
• Backwards compatibility.

Additional context
I can work on a PR proposal