Update IntelliJ Integration (rust-lang#4238)

Author: dima74

intellij.md

@@ -3,19 +3,28 @@
 ## Installation
 
 - Install [CLion](https://www.jetbrains.com/clion/), [IntelliJ Ultimate or CE](https://www.jetbrains.com/idea/) through the direct download link or using the [JetBrains Toolbox](https://www.jetbrains.com/toolbox/).
-  CLion provides a built-in debugger interface but its not free like IntelliJ CE - which does not provide the debugger interface. (IntelliJ seems to lack the toolchain for that, see this discussion [intellij-rust/issues/535](https://github.com/intellij-rust/intellij-rust/issues/535))
-  
-- Install the [Rust Plugin](https://intellij-rust.github.io/) by navigating to File -> Settings -> Plugins and press "Install JetBrains Plugin"
-  ![plugins](https://user-images.githubusercontent.com/1133787/47240861-f40af680-d3e9-11e8-9b82-cdd5c8d5f5b8.png)
+  CLion and IntelliJ Ultimate [provide a built-in debugger interface](https://github.com/intellij-rust/intellij-rust#compatible-ides) but they are not free like IntelliJ CE.
+
+- Install the [Rust Plugin](https://intellij-rust.github.io/) by navigating to File → Settings → Plugins and searching the plugin in the Marketplace
+  ![plugins](https://user-images.githubusercontent.com/6505554/83944518-6f1e5c00-a81d-11ea-9c35-e16948811ba8.png)
 
-- Press "Install" on the rust plugin
-  ![install rust](https://user-images.githubusercontent.com/1133787/47240803-c0c86780-d3e9-11e8-9265-22f735e4d7ed.png)
+- Press "Install" on the Rust plugin
+  ![install rust](https://user-images.githubusercontent.com/6505554/83944533-82c9c280-a81d-11ea-86b3-ee2e31bc7d12.png)
 
 - Restart CLion/IntelliJ
 
 ## Configuration
 
-- Open the settings window (File -> Settings) and search for "reformat"
+### Run Rustfmt on save
+
+- Open Rustfmt settings (File → Settings → Languages & Frameworks → Rust → Rustfmt) and enable "Run rustfmt on Save"
+  ![run_rustfmt_on_save](https://user-images.githubusercontent.com/6505554/83944610-3468f380-a81e-11ea-9c34-0cbd18dd4969.png)
+
+- IntellJ uses autosave, so now your files will always be formatted according to rustfmt. Alternatively you can use Ctrl+S to reformat file manually
+
+### Bind shortcut to "Reformat File with Rustfmt" action
+
+- Open the settings window (File → Settings) and search for "reformat"
   ![keymap](https://user-images.githubusercontent.com/1133787/47240922-2ae10c80-d3ea-11e8-9d8f-c798d9749240.png)
 - Right-click on "Reformat File with Rustfmt" and assign a keyboard shortcut