add a form to make a ling with 'add a participant' page

Resources/views/Event/show.html.twig

@@ -36,7 +36,7 @@
     </li>
     </ul>
             
-    <h2>{{ 'Participation'|trans }}</h2>
+    <h2>{{ 'Participations'|trans }}</h2>
     {% set count = event.participations|length %}
     <p>{% transchoice count %}%count% participations to this event{% endtranschoice %}</p>
     
@@ -74,6 +74,12 @@
             
             <ul class="record_actions">
                 <li><a href="#" class="sc-button btn-edit">{{ 'Edit all the participations'|trans }}</a></li>
+                <li><div style="padding-left: 3em;">
+                        {{ form_widget(form_add_participation_by_person.person_id, { 'attr' : { 'style' : 'width: 20em; display:inline-block; ' } } ) }}
+                        {{ form_widget(form_add_participation_by_person.submit, { 'attr' : { 'class' : 'sc-button btn-create' } } ) }}
+                        {{ form_rest(form_add_participation_by_person) }}
+                    </div>
+                </li>
             </ul>
     {% endif %}