HTML - Salto de línea

<a href="whatsapp://send?text=Comparte por redes sociales.%0AEs muy fácil.%0ATu puedes">botón de whatsapp</a>

<a href="whatsapp://send?text=Comparte por redes sociales. Es muy fácil. Tu puedes">botón de whatsapp</a>

<a href="whatsapp://send?text=Comparte%20por%20redes%20sociales.%20Es%20muy%20fácil.%20Tu%20puedes">botón de whatsapp</a>

<form id="send_menssage" data-form-output="form-output-global" data-form-type="contact" method="post">

  <div>

    <div>

      <p >Your Name</p>

      <div>

        <input id="name" type="text" name="name" data-constraints="@Required">

        <label for="name">Your Full Name</label>

      </div>

    </div>

    <div>

      <p >Your Email</p>

      <div class="form-wrap">

        <input id="contactmail" type="mail" name="contactmail" data-constraints="@Email @Required">

        <label for="contactmail">Your Email</label>

      </div>

    </div>

    <div>

      <p>Your Phone</p>

      <div>

        <input id="contactphone" type="text" name="contactphone" data-constraints="@Numeric">

        <label for="phone">Your Phone number</label>

      </div>

    </div>

    <div>

      <p>Date</p>

      <div>

        <label for="dateserv"><span class="icon icon-primary fa-calendar"></span><span>Service Date</span></label>

        <input id="dateserv" type="text" name="dateserve" data-constraints="@Required">

      </div>

    </div>

    <div>

      <p>Day Time</p>

      <div>

        <!--Select 2-->

        <select id="timeserv" name="timeserv" data-minimum-results-search="-1" data-placeholder="Desired time" data-constraints="@Required">

          <option>&nbsp;</option>

          <option value="11">11:00</option>

          <option value="12">12:00</option>

          <option value="13">13:00</option>

          <option value="14">14:00</option>

          <option value="15">15:00</option>

          <option value="16">16:00</option>

          <option value="17">17:00</option>

          <option value="18">18:00</option>

          <option value="19">19:00</option>

          <option value="20">20:00</option>

        </select>

      </div>

    </div>

    <div>

      <p>Service</p>

      <div>

        <select id="service" name="service" data-minimum-results-search="-1" data-placeholder="Select your service" data-constraints="@Required">

          <option>&nbsp;</option>

          <option value="prana">Prana Massage</option>

          <option value="hot-stones">Hot Stones Massage</option>

          <option value="relaxing">Relaxing or Swedish</option>

          <option value="tired-legs">Tired Legs</option>

          <option value="deep-tissue">Deep Tissue Massage</option>

          <option value="back">Back Massage</option>

          <option value="reflexology">Reflexology</option>

          <option value="prenatal">Prenatal</option>

          <option value="sport">Sport</option>

          <option value="facials">Facials</option>

          <option value="body-wrap">Body Wrap</option>

          <option value="Body-Exfoliation">Body-Exfoliation</option>

        </select>

      </div>

    </div>

    <div>

      <p>Persons</p>

      <div>

        <!--Select 2-->

        <select id="persons" name="persons" data-minimum-results-search="-1" data-placeholder="Persons" data-constraints="@Required">

          <option>&nbsp;</option>

          <option value="1">1</option>

          <option value="2">2</option>

          <option value="3">3</option>

          <option value="4">4</option>

        </select>

      </div>

    </div>

    <div>

    </div>

  </div>

<button id="send_message" ><span>Enviar Whatsapp</span></button>

</form>

<script>

    document.querySelector('#send_message').addEventListener('click',function(){

        var name = document.querySelector('#name').value;

        var mail = document.querySelector('#contactmail').value;

        var phonetx=document.querySelector('#contactphone').value;

        var date = document.querySelector('#dateserv').value;

        var time = document.querySelector('#timeserv').value;

        var service = document.querySelector('#service').value;

        var persons = document.querySelector('#persons').value;

        var url = "whatsapp://send?text=%20Name:%20%20"+encodeURIComponent(name)+"%0A%20E-mail:%20%20"

        +encodeURIComponent(mail)+"%0A%20Phone:%20%20"

        +encodeURIComponent(phonetx)+"%0A%20Date:%20%20"

        +encodeURIComponent(date)+"%0A%20Time:%20%20"

        +encodeURIComponent(time)+"hrs%0A%20Service:%20%20"

        +encodeURIComponent(service)+"%0A%20Persons:%20%20"

        +encodeURIComponent(persons)+"persona(s)"

        +"&phone=Tu-numero"

    window.open(url);

      });

    </script>