Add Creative Commons Attribution 3.0 license
Add Creative Commons Attribution 3.0 license

This license is used for many presentation recordings. It would be great
to have the license supported by the application directly and avoid
constantly looking for the license link.

lbryio/lbry-app,lbryio/lbry-app,lbryio/lbry-electron,lbryio/lbry-electron,lbryio/lbry-electron