libcollections link is broken

[steveklabnik]

http://doc.rust-lang.org/collections/

links to See ../std/collections for a detailed discussion of collections in Rust.

which literally links to ../std/collections rather than the correct url.

[Gankra]

Actually it links to http://std::collections, I goofed up the order of the args! 🐫 of shame

[steveklabnik]

errr yes. whoops!