Make arguments to range consistent across examples

When you're showing how to fix the `println` by using `.to_str()`, your
arguments to `range` have inexplicably changed from `(0, 100)` to `(1,
100)`. Then in your first `format!` example, the arguments are `(1, 4)`

I made all these be (1, 100); I could also see these being fixed by
being changed to (0, 100) and then changing them to (1, 101) when you
change 100 to 101 and talk about it.