Merge pull request #1901 from sillyangel/master

GitHub Codespaces

README.md

@@ -789,6 +789,7 @@ When learning CS, there are some useful sites you must know to get always inform
 - [CodePad](https://codepad.remoteinterview.io) : Code editor to try, test and run 25+ languages
 - [Coder](https://coder.com) : A Web-based development environment using Visual Studio Code as a code editor
 - [Codesandbox.io](https://codesandbox.io) : CodeSandbox makes it easier to create, share, and reuse React projects with others.
+- [Github Codespaces](https://github.com/codespaces) : Integrated cloud-based IDE directly to your browser.
 - [Github Gist](https://gist.github.com) : Instantly share code, notes, and snippets.
 - [Godbolt.org](https://godbolt.org) : Excellent tool for exploring the assembly output of different compilers with and without optimization.
 - [Ideone.com](https://ideone.com) : online compiler and debugging tool for more than 60 programming languages