Clarify hx-validate documentation (bigskysoftware#2221)

www/content/attributes/hx-validate.md

@@ -5,7 +5,7 @@ title = "hx-validate"
 The `hx-validate` attribute will cause an element to validate itself by way of the [HTML5 Validation API](@/docs.md#validation)
 before it submits a request.
 
-Form elements do this by default, but other elements do not.
+Only `<form>` elements validate data by default, but other elements do not. Adding `hx-validate="true"` to `<input>`, `<textarea>` or `<select>` enables validation before sending requests.
 
 ## Notes