Update 'README.md'

README.md

@@ -20,6 +20,7 @@ ___
 - [ZLIB](https://singlelogin.re/)
 - [Library Genesis](http://libgen.rs/)
 - [Kindle Digital Library](https://www.amazon.co.jp/hz/mycd/digital-console/contentlist/booksAll/dateDsc?pageNumber=1)
+- [SciRate](https://scirate.com/)
 - [Desmos](https://www.desmos.com/calculator)
 
 #### Reading Stack