HTML5 selected attribute (laravel#8186)

Insted of selected="selected", that sounds very old and to prevent horizzontal scroll on desktop

Author: Rattone

blade.md

@@ -819,7 +819,7 @@ In addition to public variables being available to your component template, any
 You may execute this method from your component template by invoking the variable matching the name of the method:
 
 ```blade
-<option {{ $isSelected($value) ? 'selected="selected"' : '' }} value="{{ $value }}">
+<option {{ $isSelected($value) ? 'selected' : '' }} value="{{ $value }}">
     {{ $label }}
 </option>
 ```