feat: use variable for link

Author: rettinghaus

_includes/header.html

@@ -18,7 +18,7 @@
     <a class="slackLink" target="_blank" href="https://music-encoding.slack.com/" title="MEI Slack channel">
       <svg class="logo" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M94.1 315.1c0 25.9-21.2 47.1-47.1 47.1S0 341 0 315.1c0-25.9 21.2-47.1 47.1-47.1h47.1v47.1zm23.7 0c0-25.9 21.2-47.1 47.1-47.1s47.1 21.2 47.1 47.1v117.8c0 25.9-21.2 47.1-47.1 47.1s-47.1-21.2-47.1-47.1V315.1zm47.1-189c-25.9 0-47.1-21.2-47.1-47.1S139 32 164.9 32s47.1 21.2 47.1 47.1v47.1H164.9zm0 23.7c25.9 0 47.1 21.2 47.1 47.1s-21.2 47.1-47.1 47.1H47.1C21.2 244 0 222.8 0 196.9s21.2-47.1 47.1-47.1H164.9zm189 47.1c0-25.9 21.2-47.1 47.1-47.1s47.1 21.2 47.1 47.1-21.2 47.1-47.1 47.1h-47.1V196.9zm-23.7 0c0 25.9-21.2 47.1-47.1 47.1s-47.1-21.2-47.1-47.1V79.1c0-25.9 21.2-47.1 47.1-47.1s47.1 21.2 47.1 47.1V196.9zM283.1 385.9c25.9 0 47.1 21.2 47.1 47.1s-21.2 47.1-47.1 47.1-47.1-21.2-47.1-47.1v-47.1h47.1zm0-23.7c-25.9 0-47.1-21.2-47.1-47.1s21.2-47.1 47.1-47.1h117.8c25.9 0 47.1 21.2 47.1 47.1s-21.2 47.1-47.1 47.1H283.1z"/></svg>
     </a>
-    <a class="githubLink" target="_blank" href="https://github.com/music-encoding" title="Link to GitHub">
+    <a class="githubLink" target="_blank" href="https://github.com/{{ site.github }}" title="Link to GitHub">
       <svg class="logo" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512"><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg>
     </a>
   </div>