Update _posts/2018-12-06.Rust-1.31.md

Co-Authored-By: steveklabnik <steve@steveklabnik.com>

_posts/2018-12-06.Rust-1.31.md

@@ -272,7 +272,25 @@ this is enough useful stuff to start shipping the feature itself.
 
 For full details, please see [the
 reference](https://doc.rust-lang.org/reference/items/functions.html#const-functions).
+### New tools
 
+The 2018 edition signals a new level of maturity for Rust's tools ecosystem. Cargo, Rustdoc, and Rustup have been crucial tools since 1.0; with the 2018 edition, there is a new generation of tools ready for all users: Clippy, Rustfmt, and IDE support.
+
+--- Clippy (Manish) goes here ---
+
+[Rustfmt](https://github.com/rust-lang/rustfmt) is a tool for formatting Rust code. Automatically formatting your code lets you save time and arguments by using the [official Rust style](https://github.com/rust-lang/rfcs/blob/master/style-guide/README.md). You can install with `rustup component add rustfmt` and use it with `cargo fmt`.
+
+This release includes Rustfmt 1.0. From now on we guarantee backwards compatibility for Rustfmt: if you can format your code today, then the formatting will not change in the future (only with the default options). Backwards compatibility means that running Rustfmt on your CI is practical (use `cargo fmt --check`). Try that and 'format on save' in your editor to revolutionize your workflow.
+
+IDE support is one of the most requested tooling features for Rust. There are now multiple, high quality options:
+
+* [Visual Studio Code](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust)
+* [IntelliJ](https://plugins.jetbrains.com/plugin/8182-rust)
+* [Atom](https://github.com/rust-lang-nursery/atom-ide-rust)
+* [Sublime Text 3](https://github.com/rust-lang/rust-enhanced)
+* [Eclipse](https://www.eclipse.org/downloads/packages/release/photon/r/eclipse-ide-rust-developers-includes-incubating-components)
+
+Work on IDE support is not finished, in particular code completion is not up to scratch in the RLS-based editors. However, if you mainly want support for types, documentation, and 'go to def', etc. then you should be happy.
 ### Tool lints
 
 In [Rust 1.30](https://blog.rust-lang.org/2018/10/25/Rust-1.30.0.html), we