doc: add Social Media Post

README.md

@@ -68,7 +68,7 @@ tags:
 
 ### 📅 Submission Details
 * **Submission Date:** November 2025
-* **Social Media Post:** [🔗 View on LinkedIn]() *[Coming Soon]*
+* **Social Media Post:** [🔗 View on LinkedIn](https://www.linkedin.com/posts/chen-yang-yu_huggingface-hackathon-activity-7400902296886239232-76vQ?utm_source=social_share_send&utm_medium=member_desktop_web&rcm=ACoAAEff6RgBH-oFavqAmJ2ym_c-fD-cGJqszig)
 
 
 ## 📖 Overview