Added double-quotes to link URL when printing link.

src/MdToHTML.hs

@@ -53,7 +53,7 @@ instance Show MdToken where
   show (OrdList tokens) = "ORD" ++ concatMap show tokens
   show (Code code) = show code
   show (Codeblock code) = show code
-  show (Link txt url) = "<a href=" ++ getUrl url ++ ">" ++ show txt ++ "</a>"
+  show (Link txt url) = "<a href=\"" ++ getUrl url ++ "\">" ++ show txt ++ "</a>"
   show (Image txt imgPath) = "<img src=" ++ getPath imgPath ++ ">" ++ show txt ++ "</img>"
   show (Bold token) = "<b>" ++ show token ++ "</b>"
   show (Italic token) = "<i>" ++ show token ++ "</i>"