Rollup merge of #37485 - xfix:patch-2, r=steveklabnik
Rollup merge of #37485 - xfix:patch-2, r=steveklabnik

Don't mention "*" dependency version in guessing game example

It's a bad practice as far [RFC 1241](https://github.com/rust-lang/rfcs/blob/master/text/1241-no-wildcard-deps.md) is concerned, and introducing it in early tutorial may as well make it feel legitimate.

aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,graydon/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust