Incorrect links in documentation

[tyoc213]

Here https://doc.rust-lang.org/book/getting-started.html#closing-thoughts the link

‘Learn Rust’
https://doc.rust-lang.org/book/learn-rust.html

Gives 404.

[alexcrichton]

Thanks for the report! This has been fixed on beta and nightly, so those fixes should go out for the next release.

[tyoc213]

@alexcrichton well, even if closed, I also think that the linked IRC channel for people reading the book should be now #rust-begginers

[alexcrichton]

Sure! Want to send a PR?

[tyoc213]

@alexcrichton sure why not xD! let me try!