Add FreeCodeCompiler.com IDE (#125)

Run snippets from over 19 languages including C, C++, Python, JS, Go,
Java and more. Programming guides with integrated code editor for
effective learning.

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Co-authored-by: Steven <[email protected]>

README.md

@@ -79,6 +79,7 @@ An ([IDE](https://en.wikipedia.org/wiki/Integrated_development_environment)) is
 - [myCompiler.io](https://www.mycompiler.io) - Run snippets from over 12 languages including C, C++, Java, Python, Ruby, Nodejs and more with auto code-completion, syntax highlighting, collaboration features like forking, commenting and sharing of code snippets.
 - [.NET Fiddle](https://dotnetfiddle.net) - Run C#, F# and VB.net snippets with NuGet Packages.
 - [Scastie](https://scastie.scala-lang.org) [<img title="Open Source" width="16" src="https://cdn.jsdelivr.net/npm/[email protected]/icons/github.svg" />](https://github.com/scalacenter/scastie) - Run Scala snippets with support of choosing different Scala versions, using any public library, configuring SBT settings, sharing a code snippet, embedding it into your website, etc.
+- [Free Code Compiler](https://www.freecodecompiler.com) - Run snippets from over 19 languages including C, C++, Java, Python, Go, Swift, Lua, and more with syntax highlighting, stdin, and recent snippets.
 
 ### Web Snippets