Add guidance on preferred file naming and asset selection conventions

## Overview
The Base Brand Kit includes many logo and asset files with different names and variants, but there is no documentation explaining the naming conventions or which files should be considered the default choices for common use cases.

### Problem Description
Designers and developers may be unsure which asset file to select when multiple similar options exist. Without guidance, teams may choose inconsistent files or spend extra time comparing assets to determine the correct one.

### Expected Behavior
The documentation should clearly explain how asset files are named and which variants are recommended for standard usage. Developers and designers should be able to select the correct asset quickly and confidently.

## Proposed Solution
Add a short documentation section that explains the asset naming conventions and highlights