docs: restructure README header with logo-first design

- Move PIA logo to the top for prominent brand display
- Place title 'PIA MCP Server' below logo for cleaner hierarchy
- Center both logo and title for balanced visual design
- Simplify title to shorter 'PIA MCP Server' format
- Create more impactful header layout with logo prominence

Author: dividor

README.md

@@ -2,12 +2,12 @@
 [![Tests](https://github.com/Program-Integrity-Alliance/pia-mcp-local/actions/workflows/tests.yml/badge.svg)](https://github.com/Program-Integrity-Alliance/pia-mcp-local/actions/workflows/tests.yml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
-# Program Integrity Alliance (PIA) MCP Server
-
 <div align="center">
   <a href="https://programintegrity.org/">
     <img src="https://programintegrity.org/wp-content/uploads/2024/07/PIA-Logo.svg" alt="Program Integrity Alliance" width="400"/>
   </a>
+
+# PIA MCP Server
 </div>
 
 <br/>