Update for.html.md

Boolean doesn't exist as an accepted type of variable

website/docs/language/expressions/for.html.md

@@ -98,7 +98,7 @@ maps with admin vs non-admin objects:
 ```hcl
 variable "users" {
   type = map(object({
-    is_admin = boolean
+    is_admin = bool
   }))
 }