Fix spaces in github links

Author: james-d-mitchell

themes/hugo-scroll/layouts/_default/index.html

@@ -119,7 +119,7 @@ <h3>github links</h3>
         <div class="darklinks">
               <a
             href="https://github.com/libsemigroups/libsemigroups">
-            C/C++ </a> 
+            C/C++</a> 
               <a href="https://github.com/Semigroups/semigroups">
                         GAP</a>
               <a