feat: add MIT license badge to README.md (#8871)

feat: add MIT license badge to README.md header

- Add Shields.io license badge showing 'License: MIT'
- Place badge in header section with other badges
- Link badge to LICENSE file
- Follows existing badge format (for-the-badge style)

Co-authored-by: localai-bot <localai-bot@noreply.github.com>

README.md

@@ -19,6 +19,12 @@
 </a>
 </p>
 
+<p align="center">
+<a href="LICENSE" target="blank">
+<img src="https://img.shields.io/badge/License-MIT-yellow.svg?style=for-the-badge" alt="LocalAI License"/>
+</a>
+</p>
+
 <p align="center">
 <a href="https://hub.docker.com/r/localai/localai" target="blank">
 <img src="https://img.shields.io/badge/dockerhub-images-important.svg?logo=Docker" alt="LocalAI Docker hub"/>