https://github.com/tgdwyer/tgdwyer.github.io/issues/124

Author: tgdwyer

_plugins/glossary.rb

@@ -73,7 +73,7 @@ def self.replace_glossary_terms(content, file_name)
                 match
               end
             end
-            node.replace(Nokogiri::HTML.fragment(new_content))
+            node.replace(Nokogiri::HTML5.fragment(new_content))
           end
         end
       end