Typo fix 1

Author: v-regandowner

articles/azure-resource-manager/bicep/patterns-shared-variable-file.md

@@ -39,7 +39,7 @@ When you define your resource names, use string interpolation to concatenate the
 
 ## Example 2: Network security group rules
 
-Suppose you have multiple Bicep file that define their own network security groups (NSG). You have a common set of security rules that must be applied to each NSG, and then you have application-specific rules that must be added.
+Suppose you have multiple Bicep files that define their own network security groups (NSG). You have a common set of security rules that must be applied to each NSG, and then you have application-specific rules that must be added.
 
 Define a JSON file that includes the common security rules that apply across your company: