Update 'README.md'

README.md

@@ -13,7 +13,7 @@ ___
 - [Not Even Wrong](https://www.math.columbia.edu/~woit/wordpress/)
 
 ## Resources
-- [zlib](https://singlelogin.re/)
+- [ZLIB](https://singlelogin.re/)
 - [Kindle Digital Library](https://www.amazon.co.jp/hz/mycd/digital-console/contentlist/booksAll/dateDsc?pageNumber=1)
 
 #### Reading Stack