Documentation wrong for bicop_dist Student t Distribution

[mcwachter]

Hello, this is just a documentation error but to avoid confusion I wanted to notify you about this issue. In the documentation of bicop_dist the Student t family is said to be implemented with "student" but

bicop_dist("student", 0,c(0.5,2))

returns an family not implemented error. Instead, "t" works:

bicop_dist("t", 0,c(0.5,2))

Many thanks for that great package!