Adds contributing section

_config.yml

@@ -16,6 +16,7 @@ description: > # this means to ignore newlines until "baseurl:"
 baseurl: "/open-edu" # the subpath of your site, e.g. /blog
 url: "https://ubuntu-pt.gitlab.io/open-edu" # the base hostname & protocol for your site
 twitter_username: ANSOL
+gitlab_source: ubuntu-pt/open-edu
 gitlab_username:  ubuntu-pt
 
 # Outputting

_includes/footer.html

@@ -20,6 +20,12 @@
           </li>
           {% endif %}
 
+          {% if site.gitlab_source %}
+          <li>
+            {% include icon-sourcegitlab.html username=site.gitlab_source}
+          </li>
+          {% endif %}
+
           {% if site.github_username %}
           <li>
             {% include icon-github.html username=site.github_username %}

_includes/icon-sourcegitlab.html

@@ -0,0 +1 @@
+<a href="https://gitlab.com/{{ include.username }}"><span class="icon icon--gitlab">{% include icon-gitlab.svg %}</span><span class="username">Código Fonte - Contribui!</span></a>