Update web-application-firewall.md

Author: Miskatonic-Electronic

articles/application-gateway/for-containers/web-application-firewall.md

@@ -136,7 +136,7 @@ spec:
 The following functionality is not supported on an Azure Web Application Firewall policy that's associated with Application Gateway for Containers:
 
 - **Cross-region, cross-subscription policy**: Your WAF policy must be in the same subscription and region as your Application Gateway for Containers resource.
-- **Core Rule Set (CRS) managed rules**: An Application Gateway for Containers WAF supports only Default Rule Set (DRS) 2.1 managed rule sets.
+- **Core Rule Set (CRS) managed rules**: An Application Gateway for Containers WAF supports only Default Rule Set (DRS) 2.1 managed rule set.
 - **Legacy Bot Manager Rule Set**: Bot Manager Ruleset 0.1 isn't supported, but Bot Manager Ruleset versions 1.0 and 1.1 are supported.
 - **JavaScript challenge actions on Bot Manager rules**: You can't set the action on a Bot Manager rule to JavaScript challenge.
 - **Captcha challenge actions on Bot Manager rules**: You can't set the action on a Bot Manager rule to Captcha.