Add main repository reference to template.md

Added a reference section for the main repository and project details.

Signed-off-by: Fabiana  ⚡️ Campanari <113218619+FabianaCampanari@users.noreply.github.com>

Author: FabianaCampanari

template.md

@@ -113,6 +113,22 @@ XXXX
 <!-- ========= END Confidentiality statement  ========= -->
 
 
+<!-- ========= START Main Repo REFERENCE  ========= -->
+> [!TIP]
+>
+> This repository is part of the flagship project:
+> **🔐 Cybersecurity, Social Engineering & AI Security — Main Hub**
+>
+> Explore the complete ecosystem of materials, analyses, and notebooks in the central repository:
+>
+> * 🔗 **[Cybersecurity, Social Engineering & AI Security — Main Hub Repository](https://github.com/Quantum-Software-Development/1-Cybersecurity-SocialEngineering_Main_Hub_Repository-PUCSP)**
+>
+> *Part of the Humanistic AI Data Modeling Series — where data connects with human insight… and occasionally gets socially engineered. ⚡️
+
+<br><br><br><br>
+<!-- ========= END Main Repo REFERENCE  ========= -->
+
+
 <!-- ======================================= END DEFAULT HEADER ⚡️ ===========================================  -->