Add a Copyright to footer

[tzach]

Problem

The Scylla Java driver is a fork of Datastax driver https://github.com/datastax/java-driver

Altgho the Scylla Driver project HP include the Datastax Copyright and Apache Licence[1], it would be better to include it in all pages froked from the original Datastax driver, even if it was updated.

Suggest a fix

Include the following in the footer of every page:

The ScyllaDB Java Driver is a fork of Datastax Java Driver for Apache Cassandra. See license and copyright here.

[1] https://java-driver.docs.scylladb.com/stable/index.html#license

[tzach]

@dgarcia360 how can we update the footer of this project (not the global theme)?

[Bouncheck]

Closing as completed by #196