Keep KaTeX css files

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

convert.rb

@@ -69,9 +69,12 @@ files.each do |file|
   end
 
   # If we didn't find any mathematical equations, no need to include KaTeX CSS.
-  unless found_any
-    document.css('link[href$="katex.css"], link[href$="katex.min.css"]').each(&:remove)
-  end
+  # Disabled here because Bergamot technically doesn't require math blocks
+  # on the page but does need the CSS.
+  #
+  # unless found_any
+  #   document.css('link[href$="katex.css"], link[href$="katex.min.css"]').each(&:remove)
+  # end
 
   File.write(file, document.to_html(encoding: 'UTF-8'))
 end