remove additional dots to make markdown link syntax right

`[Monads]​​..(http://www.stephendiehl.com/posts/monads.html).` to `[Monads]​​(http://www.stephendiehl.com/posts/monads.html).`

guide-zh_CN.md

@@ -611,7 +611,7 @@ PureScript有最好的JS工具链整合(用gulp/grunt/bower)，GHCJS和Haste则
 
 - [Adjunctions](http://www.stephendiehl.com/posts/adjunctions.html).
 
-- [Monads]​​(http://www.stephendiehl.com/posts/monads.html).
+- [Monads](http://www.stephendiehl.com/posts/monads.html).
 
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