Use stackoverflow-url

Author: rwinch

src/partials/toc.hbs

@@ -53,8 +53,8 @@
           Github Project
         </a>
       {{/if}}
-      {{#if page.attributes.stackOverflow}}
-        <a href="{{page.attributes.stackOverflow}}">
+      {{#if page.attributes.stackoverflow-url}}
+        <a href="{{page.attributes.stackoverflow-url}}">
           <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 384 512"><path
               d="M290.7 311L95 269.7 86.8 309l195.7 41zm51-87L188.2 95.7l-25.5 30.8 153.5 128.3zm-31.2 39.7L129.2 179l-16.7 36.5L293.7 300zM262 32l-32 24 119.3 160.3 32-24zm20.5 328h-200v39.7h200zm39.7 80H42.7V320h-40v160h359.5V320h-40z"
             ></path></svg>