Update toc.yml

Author: genlin

support/entra/entra-id/toc.yml

@@ -61,6 +61,8 @@
         href: app-integration/enable-msal4j-logging-spring-boot-webapp.md
       - name: Error AADSTS7000218 - Invalid client
         href: app-integration/confidential-client-application-authentication-error-aadsts7000218.md
+      - name: IDX10501 Signature Validation Errors
+        href: app-integration/idx10501-token-signature-validation-error.md
       - name: IDX10501 Error in ASP.NET Core with Azure B2C Custom Policy
         href: app-integration/troubleshoot-error-idx10501-aspnet-b2c.md
       - name: Infinite sign-in loop issue with ASP.NET applications