Linux Readme: remove Unix from title.
Linux Readme: remove Unix from title.

Currently BSD's and similar systems aren't supported.
lordadamson/opentoonz,m-grimaud/opentoonz,lordadamson/opentoonz,damies13/opentoonz,lordadamson/opentoonz,lordadamson/opentoonz,damies13/opentoonz,damies13/opentoonz,janisozaur/opentoonz,janisozaur/opentoonz,janisozaur/opentoonz,janisozaur/opentoonz,m-grimaud/opentoonz,janisozaur/opentoonz,m-grimaud/opentoonz,damies13/opentoonz,m-grimaud/opentoonz,lordadamson/opentoonz,damies13/opentoonz,m-grimaud/opentoonz