Add link to license folder into README.md

ReadMe.md

@@ -135,6 +135,9 @@ includeBuild('/path/to/kotlin') {
 }
 ```
 
+# License
+Kotlin is distributed under the terms of the Apache License (Version 2.0). See [license folder](license/README.md) for details.
+
 # Contributing
 
 Please be sure to review Kotlin's [contributing guidelines](docs/contributing.md) to learn how to help the project.

license/README.md

-The Apache 2 license (given in full in LICENSE.txt) applies to all code in this repository which is copyright
+The Apache 2 license (given in full in [LICENSE.txt](LICENSE.txt)) applies to all code in this repository which is copyright
 by JetBrains. The following sections of the repository contain third-party code, to which different licenses
 may apply: