Adding mastodon social network link (#651)

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## v3.0.1 (Date: TBD)
 
 - Fixed issue where if a dropdown menu was the last item in the menu bar, it did not have a proper margin on the right
+- Add social network link: Mastodon
 
 ## v3.0.0 (Date: 2020-05-07)
 

_config.yml

@@ -57,6 +57,7 @@ social-network-links:
 #  yelp: yourname
 #  telegram: yourname
 #  calendly: yourname
+#  mastodon: instance.url/@username
 
 # --- General options --- #
 

_includes/social-networks-links.html

@@ -228,4 +228,16 @@
   </li>
 {%- endif -%}
 
+{%- if site.social-network-links.mastodon -%}
+  <li class="list-inline-item">
+    <a href="https://{{ site.social-network-links.mastodon }}" title="Mastodon">
+      <span class="fa-stack fa-lg" aria-hidden="true">
+        <i class="fas fa-circle fa-stack-2x"></i>
+        <i class="fab fa-mastodon fa-stack-1x fa-inverse"></i>
+      </span>
+      <span class="sr-only">Mastodon</span>
+    </a>
+  </li>
+{%- endif -%}
+
 </ul>