Clarifications on licensing

[agriyakhetarpal]

PyBaMM has a BSD-3-Clause license, and pybamm-data has various data files from PyBaMM attributed to their respective authors. Those, in turn, come from the literature, and the restrictions on the use of such data for science and research depend on usage, their terms of service, and other commercial guarantees.

It would be great to specify a license in the README in a LICENSES.txt file for both this project (repository) and the data files, push a new v1.0.1 tag, and then create a GitHub release with this tag so that we can use v1.0.1 in the PyBaMM repository with better elucidation on the usage for these files in multiple contexts.