chore: add note about options use in numeric parameters (#12770)

docs/templates/parameters.md

@@ -266,6 +266,11 @@ data "coder_parameter" "instances" {
 }
 ```
 
+**NOTE:** as of
+[`terraform-provider-coder` v0.19.0](https://registry.terraform.io/providers/coder/coder/0.19.0/docs),
+`options` can be specified in `number` parameters; this also works with
+validations such as `monotonic`.
+
 ### String
 
 You can validate a `string` parameter to match a regular expression. The `regex`