Sentence added under Playground (#6819)

* Sentence added under Playground

Added a small sentence which would be more appropriate than the previous pr with a big definition

* Update README.md

Syntax error corrected

Co-authored-by: CleanMachine1 <78213164+CleanMachine1@users.noreply.github.com>

* Update README.md

Within your browser added

Co-authored-by: CleanMachine1 <78213164+CleanMachine1@users.noreply.github.com>

Co-authored-by: CleanMachine1 <78213164+CleanMachine1@users.noreply.github.com>

README.md

@@ -182,6 +182,8 @@ Free Podcasts and Screencasts:
 
 ### Programming Playgrounds
 
+Write, compile and run your code within a browser. Try it out!
+
 + [Chinese / 中文](more/free-programming-playgrounds-zh.md)
 + [English](more/free-programming-playgrounds.md)