fix toc

Author: vhorne

articles/web-application-firewall/toc.yml

@@ -102,7 +102,7 @@ items:
   - name: WAF and Azure Policy
     href: ./shared/waf-azure-policy.md
   - name: JavaScript challenge
-    href: ./afds/waf-javascript-challenge.md
+    href: waf-javascript-challenge.md
 - name: How-to guides
   items:
   - name: Application Gateway