docs: Lifetimes & apostrophe symbol.

[toqueteos]

Currently lifetimes has little docs on manual, I found 14 matches for "lifetime" on http://static.rust-lang.org/master/doc/rust.html

The borrowed pointers tutorial mentions named lifetimes but doesn't mention the apostrophe symbol, newcomers might get confused about that.

Same goes for manual, there's no mention to apostrophe, just some examples using 'static. It also lacks grammar production.

[huonw]

What do you mean "doesn't mention the apostrophe"? That it doesn't mention that ' introduces a lifetime?

[toqueteos]

@huonw Yep, that.
Also, 6.1.7 Static items mentions both static and 'static but doesn't clarify much the difference, unless I misread something.

[huonw]

Triage: there is still very little discussion of what a lifetime is.

[pnkfelix]

part of #11755

[steveklabnik]

We have a full lifetimes guide now.

[steveklabnik]

This is a duplicate of #8007