// Afegir just sota de <h1 class="display-3">Contacts</h1>
<div>
     <a style="margin: 19px;" href="{{ route('contacts.create')}}" class="btn btn-primary">New contact</a>
</div>


// Afegir abans de @endsection
<div class="col-sm-12">
  @if(session()->get('success'))
    <div class="alert alert-success">
      {{ session()->get('success') }}
    </div>
  @endif
</div>