Add guidelines on using logo variations for different backgrounds

## Overview
The Base Brand Kit provides several logo variations, but it is not clear which logo variant should be used for different background colors or design contexts. A quick guide on selecting the right variant would help maintain brand consistency.

## Problem Description
Without clear guidance, developers and designers may use the wrong logo variant for the background color, resulting in poor contrast and branding inconsistency.

## Expected Behavior
The documentation should clearly explain which logo versions are meant for light backgrounds, dark backgrounds, and other contexts like monochrome or icon use.

## Proposed Solution
Add a section to the documentation with examples of the logo variations in different settings, explaining when and where each variant should be used.

### Acceptance Criteria
- A “Logo Usage” section is added to the documentation.
- Clear examples show the proper use of logos for different backgrounds.
- No changes to the actual logo files are needed.