Step order help messages

[EmilHvitfeldt]

Once #147 is finished, it is going to be easier to write messages to the user related to the use steps. We don't generally do this for recipe steps, but the steps in {textrecipes} are more interconnected than most recipe steps so we will make an exception.

Say you have the following recipe

recipe(outcome ~ text, data = data) %>%
  step_bpe_tokenize(text, n_tokenns = 1000) %>%
  step_tokenfilter(text, max_tokens = 500)

This would most likely be nonsensical since the vocabulary size is defined in step_bpe_tokenize(). Having step_tokenfilter() throw a message to the user would be helpful here. Similarly step_tokenize() %>% step_tfidf() could have an message telling the user to filter the tokens before creating columns.

I would like these just to be messages with a global option textrecipes.tips to turn all of these off as there are times where the tips will be wrong.