Update toc.yml

Author: JackStromberg

articles/application-gateway/for-containers/toc.yml

@@ -34,6 +34,8 @@
     items:
      - name: Backend MTLS
        href: how-to-backend-mtls-gateway-api.md
+     - name: Path, header, and query string based routing
+       href: how-to-path-header-query-string-based-routing-gateway-api.md
      - name: SSL Offloading
        href: how-to-ssl-offloading-gateway-api.md
      - name: Traffic Splitting / Weighted Round Robin