Use `textAreaInput()` in `question_text()` initialization

[dtkaplan]

In the tutorials I write I often have essay questions. I have a custom question type for this purpose. But I realize that the current question_text() will support essays: it's just a matter of calling it with the right arguments, e.g.

```{r essay-14}
question_text("What do you think about this?", 
   answer("nice", correct=TRUE), allow_retry=TRUE, incorrect=NULL, 
   try_again_button = "Edit answer.", options=list(nrows=6))
```

I realize that this is not what question_text() was originally intended for, but it works fine and the change is very simple: change textInput to textAreaInput and perhaps allow the number of rows to be set via the question options.

question_ui_initialize.learnr_text <- function(question, value, ...) {
  textAreaInput( 
    question$ids$answer,
    label = question$question,
    placeholder = question$options$placeholder,
    value = value,
    rows = question$options$nrows %||% 1  # Keep it small for backward compatibility
  )
}

[davidkane9]

I second this request.