feat: add in configuration option for disqus

_config.yml

@@ -5,9 +5,16 @@ url: https://example.github.io
 description: "Write an awesome description for your new site here. You can edit this line in _config.yml. It will appear in your document head meta (for Google search results) and in your feed.xml site description."
 skills: "Web Developer - Graphic Artist - User Experience Designer"
 
-# Contact form: comment the line below if you want to stick with the default PHP contact form
+# Contact form:
+# - static : pass through formspree.io to validate email sending
+# - disqus : replace contact form by disqus thread
+# - comment the line below if you want to stick with the default PHP contact form
 contact: static
 
+# If you use disqus you need disqus shortname
+# https://help.disqus.com/customer/portal/articles/466208
+disqus_shortname: myshortname
+
 # Color settings (hex-codes without the leading hash-tag)
 color:
   primary: 18bc9c #80B3FF