Updated regex to support additional matching schemes (3x03, 3x03-3x04, 3x03x04)

By default, the scanner matches TV shows in the format SSxEE, and SSxEE-SSxEE for multi-episode files.
Another common format is to use SSxEExEE, e.g. 06x01x02 would be season 6 episode 1 and episode 2.
I've updated the regex pattern used to permit SSxEExEE, while still permitting SSxEE-SSxEE, and updated the comment accordingly to indicate the patterns that can match.