focus on P0 articles

Author: asergaz

articles/iot-operations/develop-edge-apps/reference-mqtt-v5.md

@@ -243,12 +243,8 @@ items:
           href: develop-edge-apps/overview-state-store.md
       - name: Reference
         items:
-          - name: 🟢MQTT v5
-            href: develop-edge-apps/reference-mqtt-v5.md
           - name: 🔵State store protocol
             href: develop-edge-apps/reference-state-store-protocol.md
-          - name: 🟢Schema registry protocol
-            href: develop-edge-apps/reference-schema-registry-protocol.md
           - name: SDKS reference documentation
             href: https://github.com/Azure/iot-operations-sdks/blob/main/doc/reference/README.md
           - name: Dapr apps