feat: add logo and favicon to documentation and README

Author: Verdenroz

.github/assets/logo.png

@@ -1,5 +1,9 @@
 # AGON
 
+<p align="center">
+  <img src=".github/assets/logo.png" alt="AGON Logo" width="200"/>
+</p>
+
 [![PyPI version](https://img.shields.io/pypi/v/agon-python.svg)](https://pypi.org/project/agon-python/)
 [![Python versions](https://img.shields.io/pypi/pyversions/agon-python.svg)](https://pypi.org/project/agon-python/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)

README.md

@@ -5,6 +5,8 @@ repo_name: Verdenroz/agon-python
 
 theme:
   name: material
+  logo: assets/logo.png
+  favicon: assets/logo.png
   font:
     text: Inter
     code: JetBrains Mono