Merge pull request #217414 from JimacoMS4/add-back-in-concepts-security-x509-toc-node-hub

Add back X.509 TOC node that was previously mistakenly deleted

Author: Court72

articles/iot-hub/TOC.yml

@@ -268,6 +268,7 @@
         - name: Security controls by Azure Policy
           displayName: regulatory, compliance, standards, domains, Azure Security Benchmark, Azure Foundations Benchmark, CMMC Level 3, FedRAMP High, FedRAMP Moderate, HIPAA HITRUST 9.2
           href: ./security-controls-policy.md
+        - name: Secure using X.509 CA certificates
           items:
             - name: X.509 CA certificate security concepts
               displayName: certificate-based authentication, cryptographic chain of trust, Device Provisioning Service (DPS), Hardware Secure Modules (HSM), self-signed certificate, Public Key Infrastructure (PKI)