Add "Try Graphviz in Your Browser" functionality to homepage

I would love to have a “Try Graphviz in your browser” – much like https://play.golang.org/p/MAohLsrz7JQ, https://www.python.org/ (“Try Python in your browser”), https://try.ruby-lang.org/, https://kotlinlang.org/, https://www.scala-lang.org/ all have linked from the homepage. Graphviz is a programming language and we can learn from the UX of other programming language websites, that trying the language is one of the first things users want to do.