Print a message pointing to the online playground if compiled without…

… it (#9622)

* Print a message pointing to the online playground if compiled without it

* Use more precise message when playground is not compiled in

This way, is more clear, that the playground and the online page
are not the same tools.

src/compiler/crystal/command.cr

@@ -77,6 +77,7 @@ class Crystal::Command
       options.shift
       {% if flag?(:without_playground) %}
         puts "Crystal was compiled without playground support"
+        puts "Try the online code evaluation and sharing tool at https://play.crystal-lang.org"
         exit 1
       {% else %}
         playground