tweak the markup module

Author: lubegasimon

src/markdown/markup.ml

@@ -53,7 +53,7 @@ let subscript i = Join (String "<sub>", Join (i, String "</sub>"))
 let superscript i = Join (String "<sup>", Join (i, String "</sup>"))
 
 let code_span s =
-  if String.contains s '`' then "``" ^ s ^ "``" else "`" ^ s ^ "`"
+  if String.contains s '`' then "`` " ^ s ^ "``" else "`" ^ s ^ "`"
 
 let link ~href i = Link (href, i)