Update README.md

Author: jacobwilliams

README.md

@@ -144,6 +144,11 @@ Documentation
 
 The API documentation can be found [here](http://jacobwilliams.github.io/json-fortran).  The documentation can also be generated by processing the source files with [RoboDoc](http://rfsber.home.xs4all.nl/Robo/).  Note that both the shell script and CMake will generate these files automatically in the documentation folder, assuming you have RoboDoc installed. 
 
+License
+--------
+
+The json-fortran sourcecode and related files and documentation are distributed under a permissive free software license (BSD-style).  See the [LICENSE](https://raw.githubusercontent.com/jacobwilliams/json-fortran/master/LICENSE) file for more details.
+
 Other Comments
 ---------------