Merge pull request #419 from OpenFn/readme_update

Readme update

Author: aleksa-krolls

README.md

@@ -28,12 +28,18 @@ website generator that uses Markdown and Javascript.
 
 ### Installation
 
+#### Unix-like systems
+
 ```console
 asdf install
 corepack enable
 yarn install
 ```
 
+#### Windows
+
+Install [nvm-windows](https://github.com/coreybutler/nvm-windows). Make sure your `node` version matches the one specified in `.tool-versions`. 
+
 ### Starting your docs site server
 
 ```console