Adds strict param for numeric rule (#10629)

* Adds strict param for numeric rule

* Update validation.md

* Update validation.md

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: peterfox

validation.md

@@ -1968,6 +1968,12 @@ The field under validation may be `null`.
 
 The field under validation must be [numeric](https://www.php.net/manual/en/function.is-numeric.php).
 
+You may use the `strict` parameter to only consider the field valid if its value is an integer or float type. Numeric strings will be considered invalid:
+
+```php
+'amount' => 'numeric:strict'
+```
+
 <a name="rule-present"></a>
 #### present