feat: Add canonical link to default layout.

Author: tonystar

_includes/default.liquid

@@ -5,6 +5,7 @@
   <link rel="icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🥷</text></svg>">
   {% comment %} @TODO: move to html.liquid {% endcomment %}
   <meta name="description" content="{{ site.description }}">
+  <link rel="canonical" href="https://bladeswitch.com/">
 {% endcapture %}
 
 {% capture body %}