Update sharing and Gemfile.

_data/share.yml

@@ -3,7 +3,7 @@
 
 platforms:
   - type: Twitter
-    icon: "fab fa-twitter"
+    icon: "fa-brands fa-square-x-twitter"
     link: "https://twitter.com/intent/tweet?text=TITLE&url=URL"
 
   - type: Facebook
@@ -16,10 +16,27 @@ platforms:
 
   # Uncomment below if you need to.
   #
-  # - type: Linkedin
-  #   icon: "fab fa-linkedin"
-  #   link: "https://www.linkedin.com/sharing/share-offsite/?url=URL"
+  - type: Linkedin
+    icon: "fab fa-linkedin"
+    link: "https://www.linkedin.com/sharing/share-offsite/?url=URL"
+
+  - type: Mastodon
+    icon: "fa-brands fa-mastodon"
+    # See: https://github.com/justinribeiro/share-to-mastodon#properties
+    instances:
+      - label: mastodon.social
+        link: "https://mastodon.social/"
+      - label: mastodon.online
+        link: "https://mastodon.online/"
+      - label: fosstodon.org
+        link: "https://fosstodon.org/"
+      - label: photog.social
+        link: "https://photog.social/"
+      - label: infosec.exchange
+        link: "https://infosec.exchange/"
+
   #
   # - type: Weibo
   #   icon: "fab fa-weibo"
   #   link: "http://service.weibo.com/share/share.php?title=TITLE&url=URL"
+  #