fix: Use full url for card iamge

Author: ripixel

templates/head.html

@@ -32,7 +32,10 @@
     property="og:description"
     content="I'm James King, and I make things for the web"
   />
-  <meta property="og:image" content="/card_{page}.png" />
+  <meta
+    property="og:image"
+    content="https://www.ripixel.co.uk/card_{page}.png"
+  />
   <meta name="twitter:card" content="summary_large_image" />
   <meta name="twitter:site" content="@ripixelcodes" />