Replace links to first edition of the Rust book with second edition

[janczer]

This is the link to first edition of the rust book:

rust/exercises/gigasecond/tests/gigasecond.rs

Line 11 in 45ac147

* https://doc.rust-lang.org/book/guessing-game.html#generating-a-secret-number

I'm not sure, maybe link to second edition would be more useful:

https://doc.rust-lang.org/book/second-edition/ch02-00-guessing-game-tutorial.html#generating-a-random-number

[ijanos]

You are right. You can create a pull request if you wish and we will merge it.

[shaleh]

This should also happen in the Getting Started doc in hello-world

[petertseng]

OK, I guess since the https://doc.rust-lang.org/book/ says "We suggest reading the second edition and then checking out the first edition later to pick up some of the more esoteric parts of the language." I guess it's prudent for all our links to go to the second edition.

It looks like this issue should be kept open until all links to specific parts in the first edition are replaced with second edition.

I think those are:

config/exercise-readme-insert.md:Make sure to read the [Crates and Modules](https://doc.rust-lang.org/stable/book/crates-and-modules.html) chapter if you
config/exercise-readme-insert.md:[crates-and-modules]: http://doc.rust-lang.org/stable/book/crates-and-modules.html
docs/ABOUT.md:Rust aims to bring modern language design and an advanced type system to systems programming. Rust does not use a garbage collector, but instead ensures safety and optimizes code at compile time. The concept of [ownership](https://doc.rust-lang.org/book/ownership.html) is how Rust achieves its largest goal, memory safety.
docs/TESTS.md:The directory must be named `src` and the file must be named `lib.rs` otherwise your code will not compile. For more details, check out the rustlang book [chapter on crates and modules](http://doc.rust-lang.org/stable/book/crates-and-modules.html)
docs/TESTS.md:Because Rust checks all code at compile time you may find that your tests won't compile until you write the required code. Even `ignore`d tests are checked at compile time. You can [comment out](https://doc.rust-lang.org/stable/book/comments.html) tests that won't compile by starting each line with a `//`. Then, when you're ready to work on that test, you can un-comment it.
exercises/bracket-push/HINTS.md:- Lifetimes and Structs: https://doc.rust-lang.org/book/lifetimes.html#impl-blocks
exercises/hello-world/GETTING_STARTED.md:Follow the [Getting Started chapter in the Rust book](https://doc.rust-lang.org/stable/book/getting-started.html).
exercises/luhn-trait/.meta/description.md:In this exercise you'll create and implement a custom [trait](https://doc.rust-lang.org/book/traits.html) that performs the validation.
exercises/luhn-trait/.meta/description.md:Note: It is [not idiomatic Rust to implement traits on on primitives](https://doc.rust-lang.org/book/traits.html#rules-for-implementing-traits). In this exercise we're showing something that you _can_ do, not something you _should_ do. If you find yourself implementing traits on primitives, perhaps you have a case of [Primitive Obsession](http://wiki.c2.com/?PrimitiveObsession).
exercises/parallel-letter-frequency/HINTS.md:- [Concurrency](https://doc.rust-lang.org/book/concurrency.html)
exercises/parallel-letter-frequency/HINTS.md:- [Benchmark tests](https://doc.rust-lang.org/book/benchmark-tests.html)
exercises/parallel-letter-frequency/HINTS.md:- [Nightly Rust](https://doc.rust-lang.org/book/nightly-rust.html)
exercises/triangle/HINTS.md:- [Enums](https://doc.rust-lang.org/book/enums.html)
exercises/triangle/HINTS.md:- [Traits](https://doc.rust-lang.org/book/traits.html)

[petertseng]

Because of #368, I believe that all actions that can currently be taken have been.

Remaining references:

$ git grep doc.rust-lang.org/book | grep -v second-edition                                                                          
exercises/decimal/.meta/description.md:- You might be able to [derive](https://doc.rust-lang.org/book/first-edition/traits.html#deriving) some of the required traits.
exercises/decimal/README.md:- You might be able to [derive](https://doc.rust-lang.org/book/first-edition/traits.html#deriving) some of the required traits.
exercises/parallel-letter-frequency/HINTS.md:- [Benchmark tests](https://doc.rust-lang.org/book/benchmark-tests.html)
exercises/parallel-letter-frequency/HINTS.md:- [Nightly Rust](https://doc.rust-lang.org/book/nightly-rust.html)
exercises/parallel-letter-frequency/README.md:- [Benchmark tests](https://doc.rust-lang.org/book/benchmark-tests.html)
exercises/parallel-letter-frequency/README.md:- [Nightly Rust](https://doc.rust-lang.org/book/nightly-rust.html)

It was our belief that as of this moment, these links do not have second-edition analogues.

From time to time, it would be appropriate to check whether the the second edition now contains analogues of the designated chapters.

If it still does not, the person who checked should post in this issue saying so.

If it does, the person who checked should create a PR that changes the chapters.

I would advise that there is no need to re-check if someone has posted in the past month, to avoid having too many people check with no result.

[coriolinus]

$ git grep doc.rust-lang.org/book | grep -v second-edition
exercises/decimal/.meta/description.md:- You might be able to [derive](https://doc.rust-lang.org/book/first-edition/traits.html#deriving) some of the required traits.
exercises/decimal/README.md:- You might be able to [derive](https://doc.rust-lang.org/book/first-edition/traits.html#deriving) some of the required traits.
exercises/macros/.meta/description.md:For further information about macros in Rust, The Rust Book has a [good chapter](https://doc.rust-lang.org/book/first-edition/macros.html) on them.
exercises/macros/README.md:For further information about macros in Rust, The Rust Book has a [good chapter](https://doc.rust-lang.org/book/first-edition/macros.html) on them.
exercises/parallel-letter-frequency/HINTS.md:- [Nightly Rust](https://doc.rust-lang.org/book/first-edition/release-channels.html)
exercises/parallel-letter-frequency/README.md:- [Nightly Rust](https://doc.rust-lang.org/book/first-edition/release-channels.html)

With the addition of the macros exercise, we've actually added to the number of exercises which contain first-edition links. Checking now, I find that no chapters have been added to the second-edition book covering any of these topics.

[petertseng]

TBD:

• Whether https://doc.rust-lang.org/book/second-edition/appendix-04-macros.html is suitable for the macros good chapter links
• Whether https://doc.rust-lang.org/book/second-edition/appendix-03-derivable-traits.html or https://doc.rust-lang.org/rust-by-example/trait/derive.html are suitable for the derive links
• Whether https://doc.rust-lang.org/book/second-edition/ch01-03-how-rust-is-made-and-nightly-rust.html is suitable for the Nightly Rust links