Auto merge of #25927 - stevegury:patch-1, r=steveklabnik

`(1..100).map(|x| x + 1)` is actually mapping [1,100) to [2,101)

Author: bors

src/doc/trpl/iterators.md

@@ -213,7 +213,7 @@ As we've said before, an iterator is something that we can call the
 `.next()` method on repeatedly, and it gives us a sequence of things.
 Because you need to call the method, this means that iterators
 can be *lazy* and not generate all of the values upfront. This code,
-for example, does not actually generate the numbers `1-100`, instead
+for example, does not actually generate the numbers `1-99`, instead
 creating a value that merely represents the sequence:
 
 ```rust