chore: update SECURITY.md (eclipse-tractusx#170)

Make SECURITY.md reflect current example of TRG 7.01 pointing to the GitHub Security Tab instead of Eclipse

SECURITY.md

@@ -1,6 +1,17 @@
-# Security Policy
-
 ## Reporting a Vulnerability
 
-Please report a found vulnerability here:
-[https://www.eclipse.org/security/](https://www.eclipse.org/security/)
+Please do **not** report security vulnerabilities through public GitHub issues.
+
+Please report vulnerabilities to this repository via **GitHub security advisories** instead.
+
+How? Inside affected repository → security tab
+
+For contributors:  
+→ Report a vulnerability
+
+For committers:  
+→ Advisories → New draft security advisory
+
+In severe cases, you can also report a found vulnerability via mail or eclipse issue here: https://www.eclipse.org/security/
+
+See [Eclipse Foundation Vulnerability Reporting Policy](https://www.eclipse.org/projects/handbook/#vulnerability)