Send basic templated email with Mailable

sample-mailable.php

<?php

public function build()
{
    return $this
        ->subject('Mail Subject')
        ->view('vendor.notifications.email')->with([
            "level" => "default",
            "greeting" => "Hi, User!",
            "introLines" => [
                "A line before the big button"
            ],
            "actionText" => "Action Button",
            "actionUrl" => url('/'),
            "outroLines" => [
                "A line after the big button"
            ]
        ]);
}