Cargo begins version number at 0.0.1 instead of 0.1.0
Cargo generates "Hello, world!" instead of "Hello world!"
`input_num` is used is used instead of `guess` further in the guide
Use new Cargo file syntax
Use new Cargo starting version number
Remove repeated section and make file path generic
auto merge of #16471 : EduardoBautista/rust/chapter-14-fixes, r=steveklabnik

Just some small fixes for the guide.  The cargo stuff is probably because of an update.