Alerts - 121314RibenSB/bootstrap GitHub Wiki
https://www.quackit.com/bootstrap/bootstrap_4/tutorial/bootstrap_alerts.cfm
<div class="alert alert-success" role="alert">Success alert</div>
<div class="alert alert-info" role="alert">Info alert</div>
<div class="alert alert-warning" role="alert">Warning alert</div>
<div class="alert alert-danger" role="alert">Danger alert</div>
<div class="alert alert-light" role="alert">Light alert</div>
<div class="alert alert-dark" role="alert">Dark alert</div>
Estas son las distitas alertas que hay