Update docs

Author: justinyoo

docs/enable-open-api-endpoints.md

@@ -111,6 +111,7 @@ namespace MyOpenApiFunctionApp
         // Add these three attribute classes below
         [OpenApiOperation(operationId: "getName", tags: new[] { "name" }, Summary = "Gets the name", Description = "This gets the name.", Visibility = OpenApiVisibilityType.Important)]
         [OpenApiParameter(name: "name", In = ParameterLocation.Query, Required = true, Type = typeof(string), Summary = "The name", Description = "The name", Visibility = OpenApiVisibilityType.Important)]
+        [OpenApiSecurity("function_key", SecuritySchemeType.ApiKey, Name = "x-functions-key", In = OpenApiSecurityLocationType.Header)]
         [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: "text/plain", bodyType: typeof(string), Summary = "The response", Description = "This returns the response")]
         // Add these three attribute classes above