Allow uploading images (#13)

Adds an optional field for the post image.

Fixes #12

Co-authored-by: clfreville2 <clement.freville2@etu.uca.fr>
Reviewed-on: https://codefirst.iut.uca.fr/git/clement.freville2/herbarium/pulls/13
Reviewed-by: Bastien OLLIER <bastien.ollier@noreply.codefirst.iut.uca.fr>

templates/post/show.html.twig

@@ -31,6 +31,12 @@
                 <th>Altitude</th>
                 <td>{{ post.altitude }}</td>
             </tr>
+            {% if post.image %}
+                <tr>
+                    <th>Image</th>
+                    <td><img src="{{ vich_uploader_asset(post, 'imageFile') }}" class="img-thumbnail" width="200" alt=""></td>
+                </tr>
+            {% endif %}
             <tr>
                 <th>Commentary</th>
                 <td>{{ post.commentary }}</td>