feat: allow for parsing first style path segment as mode

[timcreatedit]

Description

When generating tokens from styles (not variables), it would be a nice convenience feature to have figmage use the first path segment as a mode equivalent. This would allow putting these styles into the Figma file:

Color Styles:

• light/primary
• light/secondary
• dark/primary
• dark/secondary

and parsing the colors as if they were part of the light and dark mode.

Requirements

• Modify config
• Check if all modes have the same "shape" if this is active

Additional Context

This would be especially nice for all figmage users without the Figma Enterprise plan since they can't use variables in figmage.