Explicit typing in chapter 1.2 is unclear

[cheriimoya]

I've had some troubles with the comment You can change what type 31 is by providing a suffix.
It is unclear to me, a rust beginner, how to provide this suffix.
I was trying 31 i64, 31: i64and it didn't work. After a few minutes i thought "aaah it's probably not that important" and right at the beginning of chapter two, there was an example with5i32`.
I think it should already be mentioned in chapter 1.2.