Add platforms section and include WSL (#676)

README.md

@@ -9,9 +9,8 @@ Node.js version management: no subshells, no profile setup, no convoluted API, j
 
 ![usage animation](https://nimit.io/images/n/n.gif)
 
-(Note: `n` is not supported natively on Windows.)
-
 - [`n` – Interactively Manage Your Node.js Versions](#n--interactively-manage-your-nodejs-versions)
+    - [Supported Platforms](#supported-platforms)
     - [Installation](#installation)
         - [Third Party Installers](#third-party-installers)
     - [Installing Node.js Versions](#installing-nodejs-versions)
@@ -25,6 +24,13 @@ Node.js version management: no subshells, no profile setup, no convoluted API, j
     - [Optional Environment Variables](#optional-environment-variables)
     - [How It Works](#how-it-works)
 
+## Supported Platforms
+
+`n` is supported on macOS, Linux, including with Windows Subsystem for Linux, and various other unix-like systems.
+It is written as a BASH script but does not require you to use BASH as your command shell.
+
+`n` does not work in native shells on Microsoft Windows (like PowerShell), or Git for Windows BASH, or with the Cygwin DLL.
+
 ## Installation
 
 Since you probably already have `node`, the easiest way to install `n` is through `npm`: