Update programming playgrounds list with Scratch (#6485)

* Update programming playgrounds list with Scratch

Added scratch playground link in the programming playgrounds

* Update more/free-programming-playgrounds.md
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

more/free-programming-playgrounds.md

@@ -35,6 +35,7 @@
 * [Rust](#rust)
 * [RxJS](#rxjs)
 * [Scala](#scala)
+* [Scratch](#scratch)
 * [Solidity](#solidity)
 * [SQL](#sql)
 * [Svelte](#svelte)
@@ -266,6 +267,11 @@
 * [Scastie](https://scastie.scala-lang.org)
 
 
+### Scratch
+
+* [Scratch.mit.edu](https://scratch.mit.edu/create)
+
+
 ### Solidity
 
 * [ETH.Build](https://eth.build) - Austin Thomas Griffith