Clarifying license.

Author: lemire

README.md

@@ -147,3 +147,9 @@ The project can also be built via docker using default docker file of repository
 
 You may amalgamate all source files into only two files (`ada.h` and `ada.cpp`) by typing executing the Python
 3 script `singleheader/amalgamate.py`. By default, the files are created in the `singleheader` directory.
+
+### License
+
+This code is made available under the Apache License 2.0 as well as the MIT license. For unicode processing, we rely on a few functions from UniLib which are licensed under the Mozilla Public License v.2.0.
+
+Our tests include third-party code and data. The benchmarking code includes third-party code: it is provided for research purposes only and not part of the library.