Move license text to LICENSE and start README

Since a README file simply containing a license text is not that great,
I moved it out to LICENSE and started a very tiny basic README.

Added Guisepee to copyright holders. Assuming he has a joint copyright
agreement with Wikimedia Foundation Inc.

Change-Id: Iae2c93b458c6bdc023d9fd2f08e40a0056b1d00b
Merge "Move license text to LICENSE and start README"