Rename "multiplicative" parameter in theta()

[config-i1]

This is what the current implementation has:

theta(
  y,
  m = NULL,
  sign.level = 0.05,
  cost0 = c("MSE", "MdSE", "MAE", "MdAE"),
  cost2 = c("MSE", "MdSE", "MAE", "MdAE"),
  costs = c("MSE", "MdSE", "MAE", "MdAE"),
  multiplicative = c("multiplicative", "additive", "auto"),
  cma = NULL,
  outliers = NULL
)

So, multiplicative can be either "multiplicative", or "additive", or "auto". This is either a typo or Nikos trolling people. I'd suggest to rename the parameter to "seasonality" or "type".