updating license and contribution

Author: offirko

LICENSE.md renamed to LICENSE

@@ -45,7 +45,7 @@ KVStore general API may use several types of key/value storage classes, accordin
 
 ## License and contributions 
 
-The software is provided under [Apache-2.0 license](./LICENSE.md). Contributions to this project are accepted under the same license. Please see [contributing.md](./CONTRIBUTING.md) for more info. 
+The software is provided under [Apache-2.0 license](./LICENSE). Contributions to this project are accepted under the same license. Please see [contributing.md](./CONTRIBUTING.md) for more info. 
 
 This project contains code from other projects. The original license text is included in those source files. They must comply with our [license guide](https://os.mbed.com/docs/latest/reference/license.html)