Add WhatsApp to social integration (alshedivat#945)

Author: nopsqi

_config.yml

@@ -73,6 +73,7 @@ twitter_username: # your Twitter handle
 linkedin_username: # your LinkedIn user name
 scholar_userid: # your Google Scholar ID
 semanticscholar_id: # your Semantic Scholar ID
+whatsapp_number: # your WhatsApp number (full phone number in international format. Omit any zeroes, brackets, or dashes when adding the phone number in international format.)
 orcid_id: # your ORCID ID
 medium_username: # your Medium username
 quora_username: # your Quora username

_includes/social.html

@@ -1,6 +1,9 @@
             {%- if site.email -%}
             <a href="mailto:{{ site.email | encode_email }}" title="email"><i class="fas fa-envelope"></i></a>
             {% endif %}
+            {%- if site.whatsapp_number -%}
+            <a href="https://wa.me/{{ site.whatsapp_number }}" title="whatsapp"><i class="fab fa-whatsapp"></i></a>
+            {% endif %}
             {%- if site.orcid_id -%}
             <a href="https://orcid.org/{{ site.orcid_id }}" title="ORCID"><i class="ai ai-orcid"></i></a>
             {% endif %}