generate.mdl_df Broken link in documentation

[Yangzhuoran Fin Yang]

In the description of generate.mdl_df, \link doesn't show the reference properly with backticks. I guess you have to use \code{\link{}}

https://github.com/cran/fabletools/blob/50ca79c1a8815c7b4eac6fa755ad5617264e6f8e/R/generate.R#L5

[Mitchell O'Hara-Wild]

Fixed, thanks!