Update README.md

Author: yhirose

README.md

@@ -6,7 +6,7 @@ cpp-peglib
 
 C++11 header-only [PEG](http://en.wikipedia.org/wiki/Parsing_expression_grammar) (Parsing Expression Grammars) library. You can start using it right away just by including `peglib.h` in your project.
 
-You can also try the online version at https://yhirose.github.io/cpp-peglib.
+You can also try the online version, PEG Playground at https://yhirose.github.io/cpp-peglib.
 
 The PEG syntax is well described on page 2 in the [document](http://www.brynosaurus.com/pub/lang/peg.pdf). *cpp-peglib* also supports the following additional syntax for now: